Ed Westwick is being investigated by police over an allegation of rape.

The former 'Gossip Girl' actor was accused of sexually assaulting Kristina Cohen at his home three years ago in a Facebook post by the actress earlier this week, and Los Angeles Police Department (LAPD) have confirmed she has also submitted a formal complaint to them.

They said: ''Cohen came into the Hollywood police station to file a police report for sexual assault. Suspect is named as Ed Westwick. The investigation is ongoing.''

The 30-year-old actor has denied the allegation and insisted he ''doesn't know'' Kristina.

He tweeted: ''I do not know this woman. I have never forced myself in any manner, on any woman. I certainly have never committed rape.''

The 'Earthwalkers' actress claimed in her online account that the incident took place when she and an unnamed producer she was dating visited the British actor's apartment, where he suggested they had sex. When they refused, she was urged to take a nap while Ed and the producer tried to ''smooth things over''.

She continued: ''I went and laid down in the guest room where I eventually fell asleep, I was woken up abruptly by Ed on top of me, his fingers entering my body. I told him to stop, but he was strong...

''I was paralysed, terrified. I couldn't speak, I could no longer move.''

And Kristina claimed her ''nightmare'' didn't end there because her then-boyfriend blamed her for what had allegedly happened and warned her it would end her career if she spoke out.

She wrote: ''The producer put the blame on me, telling me I was an active participant. Telling me that I can't say anything because Ed will have people come after me, destroy me, and that I could forget about an acting career.

''Saying there's no way I can go around saying Ed 'raped' me and that I don't want to be 'that girl'.''