San Francisco police say they are continuing to investigate a sexual assault allegation against 49ers wide receiver Michael Crabtree, despite a published report saying that witnesses have backed Crabtree's version of events.

The San Francisco Chronicle reported Wednesday that a law enforcement source said two other women had joined Crabtree, 25, and another woman at a party in a room at the W Hotel in downtown San Francisco. The two women disputed the third woman's allegation that Crabtree had sexually assaulted her, the Chronicle reported.

A spokeswoman for the San Francisco Police Department said Wednesday morning that detectives were still working the case, which was announced Friday evening, after the team had left for the NFC Championship game in Atlanta. She also declined to comment on the Chronicle report.