CHARLOTTESVILLE, Va. - 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 details of the purported attack. The fraternity issued a statement refuting the story and the magazine apologized for a lapse in judgment and backed away from the account.

Jackie, 20, a University of Virginia junior, said that she was ambushed and raped by seven men at the Phi Kappa Psi house during a date party in 2012, allegations that tore through this campus and pushed the elite public school into the epicenter of the national discussion about how universities handle sex assault. The account described three hours of successive rapes that left Jackie blood-spattered, scarred, and emotionally devastated.

Phi Kappa Psi has said it has been working with police and has concluded the allegations are untrue. Among other things, the fraternity said there was no event at the house the night of the alleged attack.

A group of Jackie's close friends, who are sex-assault-awareness advocates at the university, said they believe something traumatic happened to her, but they also have come to doubt her account. They said details have changed over time, and they have not been able to verify key points of the story in recent days. An alleged attacker Jackie identified to them for the first time this week, for example - a junior in 2012 who worked with her as a university lifeguard - was 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.

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. He said, however, that he had never met Jackie in person and had never taken her on a date. He also said that he was not a member of Phi Kappa Psi.

Jackie affirms account

Jackie, who spoke to the Washington Post several times in the last 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 is identifying Jackie by her nickname at her request.

The prominent fraternity - which has been vilified, had its house vandalized, and ultimately suspended all of its activities on campus after Sabrina Rubin Erdely's Rolling Stone article was published 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."

Fraternity's denial

It added: "No ritualized sexual assault is part of our pledging or initiating process. This notion is vile, and we vehemently refute this claim."

U-Va. president Teresa Sullivan said 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."

Capt. Gary Pleasants, of the Charlottesville Police Department, said detectives are looking into the allegations at the request of the university but declined to comment further.

Rolling Stone's editors apologized to readers for discrepancies in the story, issuing a statement and posting it on their website. Will Dana, Rolling Stone's managing editor, said: "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.

Numerous interviews

The Washington Post interviewed Jackie several times during the last 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.

Alex Pinkleton, a close friend of Jackie's, 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.