AN IVY league fraternity has been busted hosting a disturbing sex competition they dubbed the "pig roast".

The sickening game involved the Zeta Beta Tau members racking up points at the Cornell University chapter by sleeping with overweight women. The heavier the woman, the more points awarded.

School officials said they launched a probe into the frat after receiving "multiple reports" last year regarding the cruel game, The Ithaca Voice reported.

"An investigation that concluded in January of 2018 determined that the chapter conducted a contest in which new members could accumulate 'points' by engaging in sexual intercourse with women," the university said in a statement.

Fraternity pledges were reportedly forbidden from telling the women about the contest. If there was a tie, the win would go to the member who had sex with the heaviest female, school officials said.

As a result of the investigation, the fraternity has been placed on probation for two years.

Chapter members will be required to partake in at least two events during the school's Sexual Assault Awareness Week, according to a statement issued by the university.

They also must hire a live-in adviser for the remainder of the probation period, subject themselves to external reviews and participate in "ongoing education on sexual violence," it said.

Zeta Beta Tau released a statement condemning the behaviour and expressing "mutual disgust along with those who feel hurt or victimised".

It said the contests were not sanctioned by the chapter and claimed brothers were "not aware" they were happening.

"We, too, are in disbelief and even more so that these alleged actions may have been taken by those whom we called brothers," the statement read.

"The Kappa Chapter of Zeta Beta Tau Fraternity is horrified at the notion of the degradation and/or objectification of women, and the impact it has had on men and women across the United States, and at Cornell."

The group was in the process of organising "multiple educational programs on the topics of healthy relationships and a variety of education that will positively impact our entire brotherhood".

"The allegations described are contrary to the values that Zeta Beta Tau Fraternity espouses and works in direct conflict with the beliefs and mission of the Kappa Chapter," the statement said.

"Our chapter has worked closely with the Zeta Beta Tau International Headquarters to draft and execute an action plan that addresses this alleged behaviour."