British regulators have banned a L'Oreal Revitalift skincare ad featuring an airbrushed close-up of Oscar-winning actress Rachel Weisz for exaggerating the product's age-fighting effects on a woman's complexion.

The Advertising Standards Authority ruled today that a two-page ad for L'Oreal Revitalift Repair 10, which ran in September 2011, cannot reappear "in its current form" because the black-and-white image of Weisz misrepresented what the product could do for a woman's skin. The English beauty, variously reported to be 40 or 41, took home an Academy Award for her role in  the 2005 film "The Constant Gardener."

In ruling against the world's largest cosmetics company, the agency said it took into consideration "that consumers were likely to expect a degree of glamour in images for beauty products" and that advertisers would be "keen to present their products in their most positive light using techniques such as post-production enhancement and the re-touching of images."

The agency called that approach "acceptable so long as the resulting effect was not one which misleadingly exaggerated the effect that the product was capable of achieving."

"Although we considered that the image in the ad did not misrepresent the luminosity or wrinkling of Rachel Weisz's face, we considered that the image had been altered in a way that substantially changed her complexion to make it appear smoother and more even," the authority wrote.

The ruling came in response to a complaint filed by Jo Swinson, a Scottish member of Parliament and co-founder of the Campaign for Body Confidence. Swinson, a former marketing manager, chairs a Parliamentary inquiry into causes and consequences of body image anxiety. She has succeeded with other complaints about misleading ads for cosmetics brands owned by L'Oreal. Last July, the ASA banned ads for Lancome's Teint Miracle foundation featuring actress Julia Roberts and for Maybelline's The Eraser foundation featuring supermodel Christy Turlington.

L'Oreal stands by the effectiveness of its product. It issued the following statement, as reported by MSNBC: "We believe that the image in the advertisement is a true representation of Rachel Weisz. The product claims are based on extensive scientific research which proved that the product improves 10 different signs of skin aging. We therefore do not believe that the ad exaggerates the effect that can be achieved using this product."

In another ruling today, the ASA rejected complaints that a L'Oreal moisturizer ad featuring film legend Jane Fonda had been "significantly modified."  Fonda, 74, who has appeared in an ad for L'Oreal Paris Age Re-Perfect Pro Calcium, in 2010 admitted undergoing "work" on her eyes, chin and neck, and reportedly had undergone an earlier facelift.

She made a dazzling appearance as a presenter at this year's Golden Globes awards, drawing wows from actor-director George Clooney, who said: "My God, she looked great, didn't she?"