Duchy Originals crisps were found to contain the chemical acrylamide

An organic product sold under Prince Charles's Duchy Originals brand has been found to contain elevated levels of a cancer-causing chemical.

Hand-fried vegetable crisps from the Prince's range are among a number of products identified as containing acrylamide in a study by the Food Standards Agency (FSA).

Also on the list are Hula Hoops, Ryvita, Pringles and Tesco Ginger Nut biscuits.

Acrylamide is formed when starch-rich foods are fried, baked, grilled or toasted at high temperatures.

It has been found in a wide range of home-cooked and processed foods including potato crisps, French fries, bread, crispbreads and coffee.

Concerns about acrylamide first emerged in 2002 and food companies have made determined efforts to reduce the levels in their products.

The FSA has just published the results of the first survey in a three-year programme measuring the amounts of acrylamide and two other chemicals  -  furan and ethyl carbamate  -  in food.

Its report states these chemicals 'have the potential to cause cancer even at very low levels of exposure and experts advise that exposure to these process contaminants should be as low as reasonably practicable'.

Despite its warning, the Agency said it has concluded the levels of acrylamide found during its survey 'do not increase concern about the risk to human health'.

The highest readings for acrylamide were found in Tesco own-brand potato rings, ahead of the Duchy Originals vegetable crisps.

Among the fast-food chains, acrylamide levels were highest in the chips served by KFC, ahead of McDonald's and Burger King.

Procter & Gamble, which makes Pringles, criticised the FSA for going public with its findings.

Pringles are also on the FSA list

It said: 'P&G have made significant investments in finding and implementing ways to reduce acrylamide in Pringles.

'Though the level found at the time of the FSA analysis was accurate, the sample was made over a year ago (April 2007) and does not accurately represent values that would be found today.'

United Biscuits, which makes Hula Hoops, said: 'UB has been testing approaches to reduce levels of acrylamide through working with universities and its own research.'

A spokesman added: 'As acrylamide is formed in food by common cooking practices, it is likely that people have been exposed to it in their diet for thousands of years.'

The Ryvita Company said: 'It is important to recognise that wholegrain foods, such as Ryvita crispbread, play an important role in the diet and that there is compelling evidence to show that a diet rich in whole grain foods is actually good for your health.

'Ryvita continues to be actively engaged in finding new ways of reducing acrylamide in crispbread.'

Duchy Originals group chief executive Andrew Baker said: 'We place food security and product quality at the top of our priorities.

'We are aware of the report and are currently studying the fine detail with our licensed manufacturing partner.'