Rumours are flying around Hollywood that Sienna Miller and co-star Hayden Christensen had unsimulated sex during a scene in their new film Factory Girl.

In the film Sienna plays Edie Sedgwick, Andy Warhol's Muse, as director George Hickenlooper recreates the heady days surrounding the famous artist in the 1960s.

Hayden, who played the young Darth Vader in Star Wars, also appears in the film as a love interest of Edie's and a steamy scene in which the couple make love has been causing a stir in the US.

With Hayden and the British actress reportedly becoming close off-screen, sources on the set told US tabloids the scenes were actually real.

When asked about the claims, Hickenlooper simply told reporters to "ask Sienna".

However, the actress was probably not expecting to be doorstepped about the incident when she emerged from the screening of the film at the Tribeca Grand hotel in New York - with her parents beside her.

"Oh, darling, that is so horrible," she told the reporter. "You obviously don't know anything about making movies."

Miller's publicist has denied the reports the sex scenes were real, saying it was simply tribute to Sienna's acting skills, although the publicity generated by the rumours will not do any harm for the film's takings at the box office.

02/02/2007 09:57:21