Justin, Cameron Deny Model's Sex Claims

By Stephen M. Silverman

07/22/2004 at 08:20 AM EDT

Justin Timberlake is threatening to sue Britain's News of the World after the sensational newspaper claimed he was unfaithful to girlfriend Cameron Diaz, reports TV's Celebrity Justice.

The 23-year-old pop star and the 31-year-old actress have been together for nearly a year, but last weekend News of the World ran a story in which model Lucy Clarkson – best-known in her native Britain for her impersonation of Tomb Raider character Lara Croft in a computer game – said she spent two "sizzling nights" with Timberlake while he was in London and Diaz was in Los Angeles.

In quotes making the rounds in British tabloids Thursday, Diaz is quoted as saying: "I trust Justin. This woman just wants her moment in the spotlight."

Timberlake's West Coast attorney, Martin Singer, tells Celebrity Justice that the News of the World story is untrue and that he is drafting letters to the tabloid demanding money, an apology and a retraction.

Should News of the World not respond as demanded, Singer says he will take the matter to the British courts.

Singer also is representing Britney Spears in her recent disagreement with the New York Post. The paper ran a photo of the pop princess slugging back a drink in a mini-bottle. The Post implied she was boozing it up; Spears's camp says it was an energy drink made with the herb ginseng.

While Singer reportedly has demanded money, an apology and a retraction from the Post, the paper's editor, Col Allan, has not complied.