The national organisation of the Alpha Tau Omega fraternity announced on 8 October that it had shut down the Indiana University chapter following the release of a "highly inappropriate and vulgar" video. The recently released video shows members cheering on a fraternity brother involved in a sexually explicit act with a woman.

Wynn Smiley, the national chapter's chief executive officer said the 21-year-old man in the video was an initiated member and that the two women who appeared were exotic dancers hired by the fraternity. The video, taken with a smartphone, was shot during an unauthorized event involving around half of the chapter's members.

"Our investigation revealed that no pledge was compelled to participate," Smiley said, according to CNN. "Regardless, the actions are contrary to the ideals and principles of Alpha Tau Omega and are highly offensive." He added that the chapter has been closed and its charter revoked.

A statement by the fraternity's national organisation said, "The National Fraternity, with strong encouragement from local alumni advisors, investigated the incident and took swift disciplinary action. The revocation of the chapter means the chapter is closed, effective immediately and all chapter activities must cease. The National Fraternity will continue to work closely with Indiana University officials."

In its own statement, Indiana University applauded "the national chapter's swift and strong action and is in full agreement with this decision." The university added that its office of student ethics will continue to investigate the issue to establish whether there was a violation to the university's code of student conduct.

The fraternity had earlier been suspended by the university and the national chapter pending an investigation. Allegations made on 7 October involving "credible video evidence" appeared to reveal "a purported new chapter member being encouraged to perform a sex act on a female in the presence of several other chapter members."

Indiana University-Bloomington spokesman Mark Land told reporters that the university suspended the fraternity as it looking into the hazing allegations. According to USA Today, the 29-second video making the rounds on Twitter allegedly shows a pledge - a person attempting to join the fraternity - performing the sex act on the woman as part of a hazing ritual.

The explicit video shows over a dozen men watching as the man and woman participate in the sex act on a bare mattress. Clapping, cheering and music can be heard in the background.

The latest incident is reportedly not the first time the IU chapter of the fraternity has been at the centre of a hazing investigation. In 2010, less than 20 of the 126 active members of the IU chapter were allowed to remain in the fraternity following an investigation into hazing and alcohol violations.