Brand said the man was wearing "a light green top and polka dot trousers"
Comedian Russell Brand has apologised for making a hoax call on a crime hotline during a performance on stage at a theatre in Northampton.
The star rang the police number in front of a live audience and said he had spotted a man who might be responsible for a series of assaults.
Brand said he is "devastated by the possibility" that he may have "offended vulnerable people".
Northamptonshire police have warned people against making hoax calls.
However, officers have refused to say whether further action will be taken against the star.
But a spokesman said the force would "discourage" any communication with police hotlines which was not genuine.
"I maintain that through discourse we can illuminate these dark behaviours but that ought not to be at the expense of people's feelings," Brand said in a statement on Wednesday.
The prank call was inspired by local media coverage of investigations into a number of assaults in the town in recent weeks.
Using a phone from a member of the audience he rang the crime hotline number and pretended to be a woman.
"I have seen a gentleman who fits the description," said Brand.
Video footage of the concert has been posted on YouTube.
During the call, which lasted about three minutes, the police employee asked why there was laughter in the background.
Brand said the noise - from the audience at the Royal and Derngate theatre - was from an episode of police drama The Bill, which was showing on his television.
'Polka dot trousers'
The comedian, turned actor, described the man he had seen as "wearing a lime green top and polka dot trousers.
"I thought, 'Well, look at the state of him'."
The employee ended the call after the star asked her out for dinner and began to sing down the phone.
Audience member Hannah Gee, 24, from Northampton said she thought the show was "hilarious" but could understand why the police had issued a warning about the act.
"I can see where they're coming from, because it's a Saturday night and it's a busy time for the police," she said.
"Personally, I knew it was part of the act and it was amusing, but I must admit at the time I thought it was a bit close to the bone," she added.
"I can see how it might have caused offence to some people."