The fraternity named in a discredited Rolling Stone feature about an alleged gang rape on a US college campus said Monday it will take legal action against the iconic pop culture magazine.

News of a looming lawsuit by the University of Virginia chapter of Phi Kappa Psi came a day after a Columbia University investigation faulted Rolling Stone for the way it reported and edited the story.

Published in November under the headline "A Rape on Campus," the article was pegged on a freshman named "Jackie" who claimed she had been gang-raped at the Phi Kappa Psi frat house in September 2012.

The story triggered protests, and stoked a national debate about the way US colleges handle - or mishandle - sexual assault, before it unraveled in the face of a growing number of discrepancies.

"Clearly our fraternity and its members have been defamed," said Stephen Scipione, president of the fraternity's Virginia Alpha Chapter, in a statement Monday.

"But more importantly we fear this entire episode may prompt some (sexual assault) victims to remain in the shadows, fearful to confront their attackers."

Rolling Stone retracted the story on Sunday and issued an apology on the heels of the Columbia University inquiry, which it commissioned after doubts emerged over the credibility of its source.

Published by the Columbia Journalism Review's website, the 12,000-word investigation found lapses in journalism standards at Rolling Stone from start to finish of the purported expose.

The author of the 9,000-word article, Sabrina Rubin Erdely, who still contributes to Rolling Stone, acknowledged Sunday she "did not go far enough" to verify the story.

AFP