A University of Mississippi fraternity is under investigation after brothers allegedly made sexual comments to sorority sisters participating in their annual Derby Days charity event.

The Ole Miss chapter of Sigma Chi fraternity asked members of sororities competing to be the Derby Days Queen, “Which Sigma Chi they would go down on?” and “What type of sausage would they prefer: linked or Sigma Chi?” according to a Facebook post by one Ole Miss student. A video of the event appears to show the men asking one contestant, whose initials include the letters B and J, what her nickname is.

“Bobbie Shmurda,” she appears to respond.

“So you’re telling me your nickname’s not BJ?” the emcee asks.

“We’re gonna go ahead and take BJ on that one,” another man chimes in.

“I’ll give you an easier question,” the first man says. “What’s your fondest memory of the Sigma Chi basement?”

The event includes choreographed dances by sororities in addition to the quizzing of Derby Days Queen contestants. Most videos of the event show dozens of women from the sororities dancing in carefully-choreographed unison.

“Representatives of the Title IX Office at UM are actively investigating the allegations that have been discussed on social media platforms,” the university said in a statement over the weekend. “If substantiated, the behavior reported at this event clearly violates campus policy and one of the UM community’s core values, which is for our students to show respect and dignity for all.”

The fraternity was ordered to cease Derby Day activities during a school investigation.

University spokesman Jon Scott told The Daily Beast on Monday that the school would have no further comment until its investigation concludes.

At least one student walked out of the event after watching “women be humiliated in the name of ‘philanthropy.’”

“Women were busting their asses in extremely choreographed routines some chanting ‘Sigma Chi, Sigma Chi,’ stroking the egos of guys whose only self worth is found in the letters they wear,” Abby Bruce wrote in a Facebook post. “If there are great guys in this organization, I have to wonder where they were tonight and if they were there, why they didn’t try to stop some of the things their brothers were doing. Or why they weren’t the ones with control of the microphones.”

Her post was shared more than 1,200 times and got more than 500 likes.

“Why do we pay money to participate in these events to be humiliated? Why have we allowed ourselves to be objectified? Women’s fraternities were started as an empowerment movement—what happened?” Bruce asked.

Bruce said in the Facebook post that she and a friend found at least one other woman outside who had walked out because of the comments. Her posts, as well as comments on it, suggested that some sororities required women to donate blood for the event.

“There were some comments made at this past Derby Days dance competition that just were… they were wrong. They never should have been spoken and we didn’t do enough to stop it,” Sigma Chi president Clay Wooley said in an interview Sunday, adding that the organization had opened a dialogue with sororities about future events.

Despite the criticism, this year’s Derby Days event raised 1,000 units of blood and $25,000 for a local children’s hospital, he said.

“And that’s something too important to push aside because of one really, really bad event,” he added.

An Ole Miss alumna who commented on Bruce’s post said the problems with the event went beyond just “healthy competition.” Kelci Armstrong said that when she served on the school’s Panhellenic Council from 2012 to 2013, they voted to “cease any Derby Days events for that year.”

“We did this in hopes that the men of Sigma Chi at Ole Miss would come up with a better way of hosting this event so that the Panhellenic women would have a break and recognize the importance of philanthropy,” Armstrong wrote. “Forcing people to donate blood, money, and dance is hazing. Though I think we should all do these things for the sake of philanthropy, forcing your members to do it is wrong. I am glad that I was in a house that did not force it.”

The fraternity could take a page from chapters at other universities, she suggested, and make the event “a day of field sports.”