NEW YORK — Federal prosecutors filed sex-trafficking charges Monday against Ghislaine Maxwell, the longtime companion of sex offender Jeffrey Epstein, expanding their criminal case ahead of her anticipated trial this summer.

The superseding indictment from the Manhattan U.S. attorney’s office cites a new unidentified victim who was 14 years old when Maxwell brought her into Epstein’s circle around 2001, prosecutors say, bringing the number of victims in the case to four.

The new alleged offenses also widen the time frame law enforcement is scrutinizing. In Maxwell’s original indictment, announced upon her arrest last year, the charges pertained only to suspected crimes dating to the mid-1990s. The girl cited in court papers Monday was enlisted by Maxwell and paid to give Epstein sexualized massages between 2001 and 2004, according to the new indictment.

Maxwell and Epstein compensated the girl with “hundreds of dollars in cash for each encounter” at his home in Palm Beach, Fla., and encouraged her “to recruit other girls to engage in paid sex acts with Epstein, which she did,” the document adds. Epstein employees, including Maxwell, who managed his properties, also allegedly sent her gifts, including lingerie.

Epstein, a multimillionaire who was indicted in New York in 2019, died by suicide at a federal jail here weeks later. He was previously given a lenient plea deal in Florida, despite a large number of victims who had come forward to law enforcement years ago.

Maxwell, who is slated to stand trial in July, initially was accused of recruiting and grooming Epstein’s underage victims and now faces additional counts of sex trafficking of a minor and sex trafficking conspiracy. She has maintained her innocence and is appealing the denial of her third bail application since her arrest.

Lawyers for Maxwell, 59, did not immediately respond to a request for comment. It is not clear if her legal team intends to ask for a postponement of the trial to litigate any new issues arising from the superseding indictment.

David Boies, an attorney for Epstein accuser Annie Farmer, who is part of Maxwell’s case, said Monday’s development “demonstrates that the prosecution is continuing to build its case.”

“I think it’s certainly an important addition to the case because of the age of the victim and the length of time she was trafficked,” Boies added.

Maxwell now faces eight counts in total, including perjury charges for allegedly lying during depositions in a defamation lawsuit brought against her by another Epstein accuser, Virginia Roberts Giuffre.

Dozens of women have come forward with claims that Epstein sexually abused them when they were minors. Many came from unstable homes and were drawn in by the allure of what seemed like easy money, they have said. Epstein was said to have expected multiple massages a day.

In a letter filed to U.S. District Judge Alison Nathan, prosecutors suggested that should Maxwell seek adjournment, additional charges against her are possible but that if the July 12 trial date sticks, “the Government does not intend to seek any further indictments in this case.”

Evidence has already been shared with Maxwell’s defense team covering Monday’s superseding indictment, the letter says, and prosecutors have provided additional documents to help guide Maxwell’s lawyers to the records that are relevant to the new victim, identified in court papers as “Minor Victim-4.”

Maxwell’s father was British publishing magnate Robert Maxwell. Her brother, Ian, who has been on a public relations blitz on behalf of his sister, issued a statement on Twitter after the indictment was filed.

“The government has admitted how weak its indictment is. So it has added another anonymous accuser from 20 years ago. That does not strengthen the government’s case,” his statement says.

Maxwell’s lawyers have argued she should not have been charged because Epstein’s controversial 2007 plea deal was supposed to give immunity to his potential co-conspirators. On Monday night, the U.S. attorney’s office disclosed in a letter to the judge that FBI agents in New York assisted their Florida counterparts in interviewing or trying to interview witnesses at the time, which Maxwell’s lawyers could use to bolster their argument that the deal Epstein struck with the Justice Department over a decade ago should bar her case from going forward.