Update 02/27/18: This article has been updated to reflect additional information from Michael Church, the executive director of the Sigma Chi International Fraternity.

Repeated allegations of drugging and sexual assault at Sigma Chi fraternity have been reported to leaders in the Greek community since fall 2015, according to several sources with knowledge of the incidents.

These instances of misconduct at Sigma Chi were known among Greek community leadership since about fall 2015, according to past and present leadership within the Greek community and text messages obtained by The Daily Californian. Sigma Chi was put on social probation Tuesday in response to these allegations.

In a Monday text message from Jesse Ough, the vice president of risk management for the Interfraternity Council, or IFC, to Jasmine Amerasekera, co-director of Greeks Against Sexual Assault, or GASA, Ough said he had heard of “about 12 different incidents, whether reported or just said to people since fall 2015.”

While the Panhellenic Council, or PHC, and IFC leadership have been aware of allegations, both the IFC and the PHC — which govern campus fraternities and sororities, respectively — currently lack a standard practice for responding to allegations such as those brought against Sigma Chi.

After several inquiries made by the Daily Cal, the IFC standards board announced Tuesday that the campus chapter of Sigma Chi was placed on social probation, meaning the chapter cannot sponsor, attend or participate in Greek social functions, according to the IFC constitution.

Ough went on to say in another text message that Dylan Howser, a nonstudent adviser for UC Berkeley fraternities and vice president of campus operations for UC Berkeley at the North-American Interfraternity Conference, or NIC — which represents international and national men’s fraternities — had knowledge of several incidents.

“Dylan has heard of a significant number of them,” read a text message from Ough to Amerasekera. “Other past presidents have told me about a few other ones they’ve heard, word just travels in our community faster than I can keep up lol.”

In a Monday text message, Howser said he knew of two incidents of sexual assault at Sigma Chi in fall 2016 after the cases were referred to the campus Center for Student Conduct.

“We can’t confirm an official number of allegations against Sigma Chi,” said a text message from Ough to Amerasekera on Monday. “Both because we don’t have the exact number, and because this goes far beyond our internal system and (we) do not want legal ramifications to (affect) us negatively and take more energy from our efforts to build policy that will support survivors concretely.”

On Monday, after inquiries by the Daily Cal, the PHC’s Executive Council confirmed knowledge of one incident of drugging in spring 2018 in a statement. The IFC’s Monday statement also acknowledged an incident of drugging in spring 2018.

Howser said in an email that neither he nor the NIC had “directly” received reports of misconduct. He added that allegations of chapter or individual violations are not reported to the NIC.

If survivors do share their stories, they typically do so among chapter leaders, IFC leadership or health workers, Ough said in text messages to Amerasekera.

Both the IFC and the PHC lack a regular practice for dealing with information about sexual misconduct they receive, according to Nathan Park, co-director of GASA. He added that, in the case of Sigma Chi, the survivors requested anonymity, which made it “nearly impossible” to push reports through the IFC standards board, a forum that decides punitive measures.

“A problem is that there’s no language in our bylaws that has to do with sexual violence,” Amerasekera said. “We have nothing to say, ‘If something like this (the incidents at Sigma Chi) happens, then this happens.’ ”

The issue of internally mishandling allegations and reports is not a problem “exclusive to Sigma Chi,” Park said, but rather a reflection of a broader issue throughout the Greek system.

“The basis of the problem is not having strong leadership when it comes to sexual violence,” Park said. “That in no way lets Sigma Chi off the hook — it just puts everybody on the hook. We have to figure out either how to solve it now or accept the fact that Greek life will end if we can’t decide how to solve these issues.”

The campus PHC said in the Monday statement that a “culture of toxic masculinity and misogyny” has manifested itself in the campus chapter of Sigma Chi.

Michael Church, the executive director of the Sigma Chi International Fraternity, said in an email that the international fraternity has begun an investigation into the allegation against the campus Sigma Chi chapter, adding that the chapter has been “fully cooperative” and is working “in close collaboration with the university administration.”

“Sigma Chi is committed to the health and safety of members and guests, and has taken bold measures in recent years to enhance prevention, including education efforts around sexual misconduct,” Church said in the email.