SAN FRANCISCO – Police are investigating a sexual assault allegation involving 49ers wide receiver Michael Crabtree, authorities said Friday.

The alleged assault occurred in a San Francisco hotel room early Sunday, after the 49ers’ playoff victory over the Green Bay Packers, police said in a written statement.

Crabtree has been interviewed with his attorney present and has cooperated with the probe, the statement said. The receiver hasn’t been detained or arrested, and he agreed to be available for more questions in the future.