The Daily Emerald, the Oregon student newspaper, reported that a former Oregon athlete said she filed a complaint against Prevot, accusing him of physically assaulting her twice earlier this year.
Oregon and Eugene police confirmed to ESPN.com that a report was filed but wouldn't provide further information because the investigation remained open.
Prevot's name didn't appear on Oregon's depth chart, released Friday, but a spokesperson said that might not be related to the criminal investigation. He said coach Mark Helfrich was in transit to a booster event and that the school would have no comment at this time.
A university police spokesman said any complaint of violence also would be investigated by the school's Title IX office.
Prevot, a 6-foot-3, 215-pound senior out of Houston, started five games last year and ranked eighth on the team with 48 tackles. He had moved to defensive end because the Ducks changed to a 4-3 defense under new coordinator Brady Hoke.
The Oregonian reported that Prevot had not been giving interviews during the Ducks preseason camp, which ended Thursday.
Oregons play host to UC Davis on Sept. 3 in the 2016 season opener.