Choate Rosemary Hall is known for being one of the most prestigious boarding schools in the country, an institution with alumni like President John F. Kennedy, two-time presidential nominee Adlai Stevenson and playwright Edward Albee.

The elite Connecticut private school is also a place that has for decades fostered a pattern of sexual abuse and misconduct between teachers and students, according to a troubling new internal investigation initiated by the school to address abuse allegations.

The 48-page report, which was released Thursday, was produced by Nancy Kestenbaum of Covington & Burling LLP, a former federal prosecutor, who was retained by Choate. School officials said Kestenbaum and a team of investigators spent seven months reviewing more than 23,000 pages of documents and interviewing more than 100 people, including alumni and former and current faculty, staff and trustees.

The report names 12 former Choate faculty members who engaged in what it said were substantiated instances of sexual misconduct with Choate students dating back nearly 60 years, five of whom are no longer living. The report recounts the alleged abuse in explicit detail, documenting the experiences described by 24 survivors, some of them as recently as 2010. The report notes that in some cases the school acted swiftly to address the alleged abuse, but in many cases the school failed to alert police or allowed faculty members to resign, avoiding serious legal consequences.

“The detailed content of this report is devastating to read,” board member Michael J. Carr said in a letter to the school’s community this week. “One can only have the greatest sympathy and deepest concern for the survivors. The conduct of these adults violated the foundation of our community: the sacred trust between students and the adults charged with their care.”

In a statement by the school, Choate said the school’s administration has decided to release the full contents of the independent investigator’s report in a “commitment to transparency.”

“On behalf of Choate Rosemary Hall, we profoundly apologize,” the statement said. “… The conduct of these adults violated the foundation of our community: the sacred trust between students and the adults charged with their care. We honor and thank the survivors of sexual misconduct who came forward. We hope that through this report, our community can address the issue of adult sexual misconduct in a frank and direct manner.”

“Throughout this self-examination, our goal has been to come together as a community to provide validation and support to those who suffered from abuse, to learn from the past, and to live up to the core standards outlined in Choate’s Statement of Expectations,” the statement added.

The alleged abuse highlighted by the report varies widely, ranging from inappropriate touching and kissing to sexual intercourse. The report said that the greatest number of reported incidents took place in the 1980s, with about half as much in the 1970s and 1990s, and even fewer in the 1960s and 2000s.

The report includes details about a popular English teacher and coach who it says began a sexual relationship with a 16-year-old student that took place on student trips and lasted until her college years. The report also discusses another instructor who it says kissed female students and propositioned one 15-year-old with a weekend trip where the two of them could engage in sex.

“Certain Choate graduates described themselves as having been flattered, at the time, by attention they received from faculty or staff, but told us they later recognized that the conduct had been abusive,” the report said. “… Other graduates told us of contact that they recognized as abusive at the time, including forced or coerced intercourse, as well as other incidents of unwanted contact that led students to feel betrayed by faculty or staff they had trusted and admired.”

Eric MacLeish, who represents a 1992 Choate graduate who was allegedly abused by two teachers at the school, told the Boston Globe that the scale of the abuse is unique among private schools.

“The number of people they’ve named is absolutely extraordinary,’’ MacLeish said, noting that he was impressed that the school moved quickly to produce the report.

One of the most extreme allegations of assault stems from an incident in 1999 involving a teacher at Choate from September 1998 to October 1999. The alleged assaults occurred while the teacher was the on-site Choate faculty leader of a study abroad program in San José, Costa Rica. His victims, the report said, were a 15-year-old female student who he is accused of fondling and a 17-year-old student he is accused in the report of raping in a swimming pool.

The report said a former student told investigators she and the teacher were in the pool, when he “told her he and his wife were separated [and said,] ‘I have these problems. I am a man.’ ”

Alleged witnesses, all former students, told investigators that the teacher began touching her sexually before removing his shorts and forcing her to have sex in the vicinity of other students.

The teacher was fired for “just cause’’ after the incident, but continued to teach at other schools, the report said.

The report said that “he denied that he engaged in sexual misconduct with any Choate students” when investigators interviewed him last month.