When Karen Sharman stepped on to the film set of Nine Dead Gay Guys she had never acted in her life. Minutes later she was filming her first scene - ousting two men from her club.

The 40-year-old cabaret performer plays Margaret the Iron Lady, a fearsome nightclub owner and madam, in the dark British comedy starring Stephen Berkoff, released yesterday.

Karen is well known in Brighton for her cabaret character Dolly Rocket, a larger-than-life diva.

When the film's director, Asian-British writer Lab Ky Mo, wrote the script he had had a PVC-clad Dawn French in mind for the part, but she was on tour.

Then a friend of Karen's who was working on the set suggested she try for the part.

The minute Lab Ky Mo saw the busty performer he knew she was perfect.

One of her scenes involved smothering a gay priest, who refused to pay her, with her 48H breasts.

The film, considered by some critics to be the most shocking shown at the Cannes Film Festival, is about two of young Irishmen who arrive in London to make their fortune.

Unemployed, they fall into an underground rent-boy lifestyle to supplement their Giro cheques.

While building up a clientele of gay misfits, including Golders Green, a rich Orthodox Jew, a priest and a taxi driver, they get wind of a legendary stack of cash, said to be kept under a bed.

The audience follows their antics as they scour the city for the money.

Karen admits it is not for the squeamish, but insists it is good-hearted fun.

She said: "I see it as a cross between something like a low-budget Lock Stock and Two Smoking Barrels, and a camp John Walters film like Hairspray."

Despite describing herself as a professional show-off, Karen says she was in at the deep end.

She said: "I had no acting experience. Half of me was saying: 'This is crazy'. The other half said: 'Give it a shot.'

"It's strange seeing myself on the screen. At the time I was 21-stone - that's a whole lot of PVC-clad woman.

"But after we finished filming, I was diagnosed with diabetes and have since lost eight stone."

Karen, who is on the books of Hove-based acting agency Cyber-Artists, is thinking of doing some formal acting training.

Nine Dead Gay Guys, winner of the audience award at the Montreal film festival, opened at the Odeon, Brighton, for a week yesterday.

Lab Ky Mo will be at The Odeon on Sunday to give a talk about the film and answer questions.

To book tickets, call The Odeon on 0870 5050007.