By Stephen M. Silverman
Updated November 11, 2003 10:30 AM

Fresh from her hollow court victory in London — where she was awarded a paltry $24,000 from a magazine that published unauthorized photos of her wedding — Catherine Zeta-Jones and her lawyers are back in action.

This time, the “Chicago” Oscar winner, 33, is bent out of shape by reports that she lost weight thanks to the high-protein Atkins diet, reports the Smoking Gun Web site, which has published a warning letter sent last week to media outlets by Zeta-Jones’s Century City law firm Lavely & Singer.

The letter says that the firm has become aware that Zeta-Jones’s “likeness and persona have been improperly linked” to the “world-renowned Atkins diet” in certain media outlets.

“Nothing could be further from the truth,” the letter states.

The firm also says the weight-loss program “has been derided by nutritionists and other health care officials for decades.”

By incorrectly reporting that the star “uses and/or endorses the Atkins diet,” the letter states, publications are “falsely representing to the average reader, including many young women who look up to my client and admire her beautiful appearance, that Ms. Zeta-Jones would recommend this diet to any person looking to lose weight.”

Claiming that a link to Atkins could hurt Zeta-Jones’s ability to land endorsement deals for “health-related products,” attorney John H. Lavely writes, “In essence, my client is being made to look as if she’s more concerned about her outward appearance than she is with serious health concerns.” (Zeta-Jones currently endorses a cellular phone company.)

Such publications as the New York Post and London’s Sunday Telegraph have claimed Zeta-Jones was following the Atkins program. But the Smoking Gun notes an Oct. 20 PEOPLE story quoting a source close to the famously curvy star who shot down the diet stories, claiming that the actress “eats what she wants” and exercises regularly.

Richard Rothstein, spokesman for the Atkins Nutritional Institution, tells the Smoking Gun that his company has heard from Zeta-Jones’s lawyers. Furthermore, he said, “It’s never been our policy to seek celebrity endorsements. … Where tabloids get their info is a complete mystery to us.”