An aquaculture company, Johnson Seafarms, claims to have successfully developed the sustainable organic cultivation of cod - a difficult fish to farm - and created what it claims is the most environmentally friendly seafood in the world.

The project has backing from the Organic Food Federation, the RSPCA, Marine Conservation Society and the Soil Association. And, after a high-profile trial run in Hollywood, it now features on the menu of one of the world's most exclusive restaurants, the French Laundry in California's Napa Valley, where fish dishes can cost more than £75.

Hollywood stars such as Demi Moore and Pierce Brosnan have already given their seal of approval. And, from this year, the upmarket cod will be launched in UK supermarkets.

Moore highlighted the health benefits of the fish at a fundraiser for her charity, Children's Health Environmental Coalition, which is dedicated to highlighting the dangers of environmental toxins that can affect children's health. Ben Ford, a chef and the son of the actor Harrison Ford, prepared a special cod dish for a dinner for his father's friend, Brosnan, at the Sundance Film Festival.

Now Johnson's is negotiating a deal to provide fish to some of the UK's top restaurants and placing it on the menu of the luxury range of food offered by Waitrose, Tesco and Sainsbury's.

Starting in May the company is planning to harvest 2,000 tons of fish - the first significant harvest since the project was started four years ago.

It is estimated that in Britain consumers eat approximately 270,000 tons of cod a year but, as North Sea stocks continue to shrink to less than one-tenth of their 1970 levels, the seafood industry has been looking for a sustainable alternative supply.

From the descendants of about 100 wild cod caught off Shetland coastal waters in 2003 the company plans to eventually harvest up to two million cod every year.

Johnson's claims that the 100 per cent organic pre-packaged fillets are guaranteed to come from fish reared in environmentally-sustainable conditions and to have never come into contact with any dyes, pesticides or chemicals.

Raised in special circular cages, where they are constantly monitored by a remote-controlled robotic camera, the fish are fed choice off-cuts of wild herring and mackerel harvested for human consumption.

No chemicals are used and the double layer of nets that surround each cage are manually cleaned every six weeks without the use of anti-fouling chemicals.

"We have exceeded all known welfare standards for these fish," said a company spokesman.