The Los Angeles Police Department is investigating 28 sex crimes involving those working in Hollywood and the media.
Force chief Charlie Beck told Deadline that more are also likely.
Among those being investigated are producer Harvey Weinstein, British actor Ed Westwick (above) from Gossip Girl and the recent comedy White Gold and Murray Miller, a writer on HBO show Girls.
“We anticipate the LAPD and other jurisdictions will receive even more high profile sex crime reports in the coming weeks and months,” he said.
“We encourage all victims of sexual assault to come forward to report these crimes.
“We recognize the significant trauma these victims suffer at the hands of the predators who commit these heinous crimes.
“Our detectives are coordinating closely with our local prosecutors and other police agencies, including the NYPD.
“The high-profile nature of these particular cases has not changed our unyielding commitment to seek justice for ALL victims of sexual assault.”
Westwick has been accused of raping two women, with both of the alleged assaults said to have occurred under similar circumstances.
He denies the allegations, writing in a social media post: “It is disheartening and sad to me that as a result of two unverified … social media claims, there are some in this environment who could ever conclude I have had anything to do with such vile and horrific conduct. I have absolutely not.”
The BBC has delayed the premiere of Ordeal By Innocence, a new drama starring the actor, ‘until these matters are resolved’.
As well as the 27 open cases, a further 37 other sex crimes are being investigated by other jurisdictions than the LAPD.