With its Gothic romance, golden velvet sofas and steep prices, Julie's in London makes no secret of its reputation as a celebrity hangout. Kate Moss, Gwyneth Paltrow, Colin Firth, Kylie Minogue, Jeremy Paxman and U2 are just a few of the glitzy guests the restaurant lists on its website.

As part of its commitment to fine dining, Julie's proclaims its use of organic food, which it says keeps the earth healthy and minimises pesticide residues.

But what it fails to mention is that guests who ordered organic dishes last winter were routinely cheated by the restaurant, which bought cheap meat and pocketed the change.

Now it has emerged that so great was the swindle uncovered by environmental health officers when they visited the kitchens of one of the oldest fixtures on the capital's dining scene, that its manager only just escaped prison last week.

At West London magistrates' court last Tuesday, Johnny Ekperigin, Julie's managing partner, was fined £7,500 and ordered to pay the council's costs of £4,297 for breaching the 1990 Food Safety Act. He was warned that if he re- offended, he would be jailed.

The case is damaging to the fashionable reputation of Julie's and to Ekperigin, who also manages the swish Portobello Hotel.

Julie's is prized by celebrities because it offers glamour and privacy in abundance. Guests may enjoy the opulence of the Champagne Bar with its intricate Islamic carvings, or the medieval private banqueting room, or the alcoves that frustrate prying eyes.

"It is home to a rich mix of artists as well as people in publishing, film and the media. Every Hollywood A-lister has dined at Julie's for over 30 years. You name them, they've been here," Julie's says. Celebrities are rumoured to escape the paparazzi by a back door.

But there was no escape for the restaurant when inspectors from Kensington and Chelsea council called for a routine inspection on 21 November last year.

They saw that the menu had organic marinated roast chicken, sausages, and spice-crusted rack of lamb and decided to check the kitchens. They found no trace of anything organic on delivery notes. The suppliers were traced and confirmed they had not supplied organic meat to the restaurant for the 52 days before the inspection.

Between 1 October and 21 November 2005, the council estimated the restaurant had saved £4,186 on chicken alone. Kensington and Chelsea decided to mount what it claimed yesterday was the first prosecution for the fraudulent sale of organic food by a restaurant.

Fiona Buxton, a councillor responsible for public health, said: "This was a very serious case indeed, and customers have a right to expect to receive what is advertised on the menu. For many visitors to the restaurant, this has led to a betrayal of lifestyle."

She added: "Consumers buy into the idea of organic food either due to the health implications or in support of good animal husbandry. Julie's Restaurant has cheated them of these values." She said she hoped the scale of the fine would send a "stark warning" to other restaurateurs.

A spokesman for the Soil Association said: "The genuine success of the growth in organic food and drink sales must be protected from fraudsters seeking to put profits before principles."