— A University of Virginia student’s harrowing description of a gang rape at a fraternity, detailed in a recent Rolling Stone article, began to unravel Friday as interviews revealed doubts about significant elements of the account. The fraternity issued a statement rebutting the story, and Rolling Stone apologized for a lapse in judgment and backed away from its article on the case.

Jackie, a U-Va. junior, said she was ambushed and raped by seven men at the Phi Kappa Psi house during a date party in 2012, allegations that tore through the campus and pushed the elite public school into the center of a national discussion about how universities handle sex-assault claims. Shocking for its gruesome details, the account described Jackie enduring three hours of successive rapes, an ordeal that left her blood-spattered and emotionally devastated.

The U-Va. fraternity where the attack was alleged to have occurred has said it has been working with police and has concluded that the allegations are untrue. Among other things, the fraternity said there was no event at the house the night the attack was alleged to have happened.

A group of Jackie’s close friends, who are advocates at U-Va. for sex-assault awareness, said they believe that something traumatic happened to her, but they also have come to doubt her account. A student who came to Jackie’s aid the night of the alleged attack said in an interview late Friday night that she did not appear physically injured at the time but was visibly shaken and told him and two other friends that she had been at a fraternity party and had been forced to have oral sex with a group of men. They offered to get her help and she said she just wanted to return to her dorm, said the student, who spoke on the condition of anonymity because of the sensitivity of the subject.

The friends said that details of the attack have changed over time and that they have not been able to verify key points in recent days. For example, an alleged attacker that Jackie identified to them for the first time this week — a junior in 2012 who worked with her as a university lifeguard — was actually the name of a student who belongs to a different fraternity, and no one by that name has been a member of Phi Kappa Psi.

(Related: U-Va. and sexual assault: The scrutiny will continue)

Reached by phone, that man, a U-Va. graduate, said Friday that he worked at the Aquatic and Fitness Center and was familiar with Jackie’s name. But he added that he never met Jackie in person and never took her out on a date. He also said he was not a member of Phi Kappa Psi.

Jackie, who spoke to The Washington Post several times during the past week, stood by her account, offering a similar version and details.

“I never asked for this” attention, she said in an interview. “What bothers me is that so many people act like it didn’t happen. It’s my life. I have had to live with the fact that it happened — every day for the last two years.”

A lawyer who is representing Jackie said Friday that she and her client are declining to comment beyond her interviews. The Post generally does not identify victims of sexual assault without their permission, and The Post is identifying Jackie by her real nickname at her request.

The prominent fraternity — which has been vilified, vandalized and ultimately suspended on campus since Sabrina Rubin Erdely’s Rolling Stone article went online last month — said in its statement Friday that its “initial doubts as to the accuracy of the article have only been strengthened as alumni and undergraduate members have delved deeper.”

Phi Kappa Psi said it did not host “a date function or social event” during the weekend of Sept. 28, 2012, when Jackie alleges that she was invited to a date party, lured into an upstairs room and then ambushed and gang-raped by seven men who were “rushing” the fraternity.

The fraternity also said it has reviewed the roster of employees at the university’s Aquatic and Fitness Center for 2012 and found that it does not include a member of the fraternity — a detail Jackie provided in her account to Rolling Stone and in interviews with The Post — and that no member of the house matches the description detailed in the Rolling Stone account. The statement also said that the house does not have pledges during the fall semester.

“Moreover, no ritualized sexual assault is part of our pledging or initiating process,” the fraternity said. “This notion is vile, and we vehemently refute this claim.”

U-Va. President Teresa A. Sullivan said Friday that the developments will not alter the university’s focus on “one of the most difficult and critical issues facing higher education today: sexual violence on college campuses.”

“The University remains first and foremost concerned with the care and support of our students and, especially, any survivor of sexual assault,” Sullivan said in a statement. “Our students, their safety, and their well-being, remain our top priority.”

Sullivan vowed to continue taking a “hard look” at the school’s practices, policies and procedures.

Capt. Gary Pleasants of the Charlottesville police said detectives are looking into the allegations at the request of the university, but he would not comment on the status of that investigation. “Our purpose is to find the truth in any matter, and that’s what we are looking for here,” Pleasants said. “These articles do not change our focus moving forward.”

Rolling Stone’s editors apologized to readers for discrepancies in the story, issuing a statement and posting it on their Web site. Will Dana, Rolling Stone’s managing editor, said there is fresh doubt about the article.

“In the face of new information, there now appear to be discrepancies in Jackie’s account, and we have come to the conclusion that our trust in her was misplaced,” he said in the statement.

The Post interviewed Jackie several times during the past week and has worked to corroborate her version of events, contacting dozens of current and former members of the fraternity, the fraternity’s faculty adviser, Jackie’s friends and former roommates, and others on campus.

Speaking for the first time since the details of her alleged sexual assault were published in Rolling Stone, the 20-year-old student told The Post that she is not wavering from her version of events. In lengthy in-person interviews, Jackie recounted an attack very similar to the one she presented in the magazine: She had gone on a date with a member of the house, went to a party there and ended up in a room where she was brutally attacked — seven men raping her in succession, with two others watching.

Alex Pinkleton, a close friend of Jackie’s who survived a rape and an attempted rape during her first two years on campus, said in an interview that she has had numerous conversations with Jackie in recent days and now feels misled.

“One of my biggest fears with these inconsistencies emerging is that people will be unwilling to believe survivors in the future,” Pinkleton said. “However, we need to remember that the majority of survivors who come forward are telling the truth.”

Pinkleton said she is concerned that sexual assault awareness advocacy groups will suffer because of the conflicting details of the Rolling Stone allegations.

“While the details of this one case may have been misreported, this does not erase the somber truth this article brought to light: Rape is far more prevalent than we realize, and it is often misunderstood and mishandled by peers, institutions and society at large,” Pinkleton said. “We in the advocacy community at U-Va. will continue the work of making this issue accessible to our peers, guiding the conversation and our community into a place where sexual assaults are rare, where reporting processes are clear and adjudication is fair and compassionate.”

The fraternity’s statement came two weeks after Rolling Stone ran a lengthy article about what it characterized as a culture of sex assault at the flagship state university, using Jackie’s story to illustrate how brazen such attacks can be and how indifferent the university is to them.

The article, published in the Dec. 4 issue of the pop culture magazine, led to headlines around the world and rekindled college campuses’ discussions about sexual assault, sending U-Va.’s administration scrambling to respond. The article spawned protests and vandalism, and the university quickly suspended all Greek system activities until the beginning of next semester and put out a call for zero tolerance of sexual assault.

The Rolling Stone allegations shook the campus at a tumultuous moment, as the university was still mourning the death of U-Va. sophomore Hannah Graham. Her body was found five weeks after she disappeared in Charlottesville. Jackie’s story empowered many women to speak publicly about attacks on them, but it also immediately raised questions about the decisions Jackie made that evening — not going to a hospital or reporting the alleged crime to police or the school — while some expressed doubt about her story altogether.

Although Jackie shared elements of her story at a Take Back the Night event at the university, she told The Post that she had not intended for it to reach a wider audience until the Rolling Stone writer contacted her.

“If she had not come to me, I probably would not have gone public about my rape,” said Jackie, adding that she had been diagnosed with post-traumatic stress disorder and is taking antidepressants.

Earlier this week and for the first time, Jackie revealed to friends the full name of her alleged main attacker. After looking into that person’s background, the group that had been among her closest supporters quickly began to raise suspicions about her account. The friends determined that the student Jackie had named was not a member of Phi Kappa Psi and that other details about his background did not match information Jackie had disclosed earlier about the attacker she knew.

A student identified as “Andy” in the Rolling Stone article said in an interview with The Post Friday night that Jackie did call him and two other friends for help a few weeks into the fall semester in 2012. He said Jackie said that “something bad happened” and that he ran to meet her on campus, about a mile from the school’s fraternities.

The student, who said he never spoke to a Rolling Stone reporter, said Jackie seemed “really upset, really shaken up” but disputed other details of that article’s account. Rolling Stone said that the three friends found Jackie in a “bloody dress,” with the Phi Kappa Psi house looming in the background, and that they debated “the social price of reporting Jackie’s rape” before advising against seeking help. He said none of that is accurate.

“Andy” said Jackie said she had been at a fraternity party and had been forced to perform oral sex on a group of men, but he does not remember her identifying a specific house. He said he did not notice any injuries or blood but said the group offered to get her help. She, instead, wanted to return to her dorm, and he and the friends spent the night with her to comfort her at her request.

“The perception that I’m gravitating toward is that something happened that night and it’s gotten lost in different iterations of the stories that have been told,” said the student who requested anonymity. “Is there a possibility nothing happened? Sure. I think the truth probably lies somewhere in the middle.”

Emily Renda was a U-Va. senior when she met Jackie in the fall of 2013. In an interview, Renda said she immediately connected with Jackie as they discussed the bond they shared as rape survivors. Renda said she was raped her freshman year after attending a fraternity party.

Jackie told The Post that she wept as she spoke to Renda about her own sexual assault.

Renda said Thursday that Jackie initially told her she was attacked by five students at Phi Kappa Psi. Renda said she learned months later that Jackie had changed the number of attackers from five to seven.

“An advocate is not supposed to be an investigator, a judge or an adjudicator,” said Renda, a 2014 graduate who works for the university as a sexual violence awareness specialist. But as details emerge that cast doubt on Jackie’s account, Renda said, “I don’t even know what I believe at this point.”

“This feels like a betrayal of good advocacy if this is not true,” Renda said. “We teach people to believe the victims. We know there are false reports, but those are extraordinarily low.”

Renda said research shows that between 2 and 8 percent of rape allegations are fabricated or unfounded.

“The doubt cast on Jackie’s story has been feeding the myth that we have been combating for 40 years — that women lie about rape. And I feel that will put women at a disadvantage in coming forward,” Renda said.

In July, Renda introduced Jackie to Erdely, the Rolling Stone writer who was on assignment to write about sexual violence on college campuses. Overwhelmed by sitting through interviews with the writer, Jackie said she asked Erdely to be taken out of the article. She said Erdely refused, and Jackie was told that the article would go forward regardless.

Jackie said she finally relented and agreed to participate on the condition that she be able to fact-check her parts in the story, which she said Erdely agreed to.

“I didn’t want the world to read about the worst three hours of my life, the thing I have nightmares about every night,” Jackie said.

In an e-mail message, Erdely said she was not immediately available Friday, and she and Rolling Stone did not return messages seeking comment.

In a series of tweets late Friday, Dana, Rolling Stone’s managing editor, said that he “can’t explain the discrepancies between Jackie’s account and the counter statements by Phi Psi” and that “the fact that there is a story that appears in Rolling Stone in which I don’t have complete confidence is deeply unsettling to me.”

Dana tweeted that the reporters and editors at Rolling Stone made a judgment to come to an agreement with Jackie not to contact her alleged attackers, a judgment that, he wrote, ended up being wrong. “That failure is on us — not on her,” he wrote.

Jackie told The Post that she felt validated that the article encouraged other female students to come forward saying that they, too, had been sexually assaulted in fraternity houses.

“Haven’t enough people come forward at this point?” she said. “How many people do you need to come forward saying they’ve been raped at a fraternity to make it real to you? They need to acknowledge it’s a problem. They need to address it instead of pointing fingers to take the blame off themselves.”

As classes resumed this week after Thanksgiving break, Jackie, whose family lives in Northern Virginia, returned to the campus where her story is still a daily topic of conversation. Although anonymous for now, she said she remains afraid that fellow students and fraternity members will somehow recognize her as the victim from the Rolling Stone article.

Jackie said she never wanted to go to U-Va. Graduating near the top of her high school class of 700, she had planned to attend Brown University. She dreamed of pursuing a career in medicine, like her childhood hero, Patch Adams.

“I wanted to help people,” Jackie said.

She said she was disappointed when her family told her that they could not afford the Ivy League tuition. She enrolled at U-Va. without ever visiting the school.

She said she performed well in course work includeding pre-med classes in psychology, chemistry and religious anthropology. She said she soon found a job as a lifeguard at a campus pool, where she said she met a charming junior who had dimples, blue eyes and dark, curly hair.

Jackie told The Post that the student later took her out for an extravagant dinner at the Boar’s Head before they attended a date function on Sept. 28, 2012, at his fraternity, Phi Kappa Psi. Jackie said her date appeared to have orchestrated the sexual assault by attempting to ply her with alcohol before escorting her into a darkened room upstairs. Jackie said she did not drink alcohol that night because she was taking migraine medication.

According to her account in Rolling Stone and in interviews, Jackie said she was thrown to a rug, breaking a low glass table in the process. She said she was cut on the back of her arm as a result but noted that her attack happened on a thick rug.

Jackie told The Post that the men pinned her down and then raped her, the trauma leaving her bleeding from between her legs.

“One of them said ‘Grab its [expletive] leg,’ ” she said, her lip quivering and tears streaming down her face. “ ‘Its.’ I’ll never forget that. I felt like nothing, like I wasn’t even human.”

Jackie said she didn’t go to a hospital or report the crime because she was new to campus and unaware of the resources available to her. She said the idea of recounting events to police terrified her. “I didn’t know what to do,” she said.

Jackie’s former roommate, Rachel Soltis, said she noticed emotional and physical changes to her friend during the fall semester of 2012, when they shared a suite.

“She was withdrawn, depressed and couldn’t wake up in the mornings,” said Soltis, who said that she was convinced that Jackie was sexually assaulted. Soltis said that Jackie didn’t tell her about the alleged sexual assault until January 2013. Soltis said she did not notice any apparent wounds on Jackie’s body at the time of the alleged assault.

The Post asked Jackie numerous times to reveal the full name of the two attackers she said she recognized. She declined, saying she didn’t want the perpetrator “to come back in my life.”

Jackie said numerous times that she did not expect that a police investigation would lead to any charges. She said she knew there was little, if any, forensic evidence that could prove the allegations two years afterward.

“I didn’t want a trial,” Jackie said. “I can’t imagine getting up on a defense stand having them tear me apart.”

Jackie said early in the week that she felt manipulated by the Rolling Stone reporter, adding that she “felt completely out of control over my own story.” In an in-person interview Thursday, Jackie said the Rolling Stone account of her attack was truthful, but she also acknowledged that some details in the article might not be accurate.

Jackie contradicted an earlier interview, saying Thursday that she did not know whether the attacker she knew actually was a member of Phi Kappa Psi.

“He never said he was in Phi Psi,” she said, while noting that she was positive that the date function and attack occurred at the fraternity house. “I know it was Phi Psi, because a year afterward, my friend pointed out the building to me and said that’s where it happened.”

Nick Anderson, Paul Farhi, Jennifer Jenkins and Julie Tate contributed to this report.