The hotel-room sexual assault allegations against 49ers star wide receiver Michael Crabtree do not appear to be holding up under investigation. San Francisco police said Friday that they were looking into a complaint that Crabtree had assaulted a woman in a hotel after the Niners defeated the Green Bay Packers in a playoff game Jan. 12. According to a San Francisco law enforcement source, the woman who lodged the allegation was one of three women who joined Crabtree in a party at a room in the tony W Hotel on Third Street. The other two women have told investigators that Crabtree didn’t assault anyone, said the source, who spoke on condition of anonymity because the investigation is continuing. Police haven’t found any physical evidence of an attack, the source added and it hasn’t been disclosed whether the woman who said she had been victimized went to a hospital to be examined. Source: San Francisco Chronicle