OSU's popular FarmHouse Fraternity has been rocked by allegations a former member sexually assaulted other members.
The University says it launched an investigation November 12, but OSU leaders say federal law prohibited them from telling Stillwater Police until last Friday.
Police say they've interviewed at least three alleged victims, and they believe there are more.
FarmHouse President Nick Jordan says the fraternity has nothing to hide.
"We immediately turned the matter over to the University, none of the actions occurred in the house, and that individual is no longer associated with us," he said.
Stillwater police say numerous agencies are involved in this investigation.