The BBC's Nicola Carslaw reports: "More than a quarter of food samples showed pesticide residues"

A government report shows that traces of chemicals, some suspected of causing cancer, were found in a small percentage of food stuffs.

Consumers' and environmental groups immediately demanded action to restore consumer confidence already shaken by the row over genetically-modified food and the BSE crisis.

But food experts say the residues present no cause for alarm.

Professor Ian Shaw, independent chairman of the Working Party on Pesticide Residues (WPPR), which produced the report, said the findings were "reassuring".

The report showed that 73% of foods tested had no detectable residues of pesticides and 26% had residues below maximum residue limits.

Dangerous pesticides

But 1.3% were found to have levels above the limit.

Pears were found to contain chlormequat, a growth regulator used in Holland and Belgium, while there was evidence of the illegal use of the fungicide iprodione in lettuce.

Round lettuce was found to contain excessive levels of the organophosphate Malathion.

Another food scare hits the supermarket aisles

Corned beef was found to contains traces of some of the most dangerous pesticides including DDT, a suspected carcinogen.

Another probable cancer causing agent, lindane, appeared in chocolate.

But Professor Shaw, Head of Toxicology at the University of Central Lancashire, said: "The results demonstrate clearly that residues in food are not a cause for concern.

"None of the evidence here raises concern for human health, including babies and toddlers."

Researchers subjected about 3,000 samples of food from retailers across the UK to 90,000 tests for 100 pesticides.

Consumers' and environmental groups have demanded action over the use of pesticides in food.

The Consumers' Association said the findings of the pesticide report were particularly worrying in the light of existing consumer concern about food safety.

'Need more checks'

The Soil Association, an organic farming pressure group, said the build-up of pesticide residues in food was "inevitable" given modern farming methods.

Health minister Baroness Hayman: ''The main message is a reassuring one on the public health front''

And Friends of the Earth said additional inspections were needed at farms to see how many pesticides were being used, and if any of these were illegal varieties.

Food campaigner Pete Riley said: "We need a rigorous system of checks and inspections to ensure that when an apple or a tomato hits our plate we can eat it with full confidence."

Liberal Democrat agriculture spokesman Paul Tyler said foreign food imports were at the heart of the problem.

He said: "Successive governments, no doubt influenced by their paymasters in the supermarket chain, have turned a blind eye to cut-price foods from abroad, ignoring the potential health costs."

Greenpeace called for action to reduce chemicals in food by providing further funding for research into sustainable organic farming methods.

'Switch to organic'

Director Dr Doug Parr said: "This level of chemicals in our food is the inevitable result of 50 years of industrial agriculture in the UK.

"The solution is not just more testing but changing agricultural policy.

"The public want to know they are eating healthy produce. This means going organic."

But the National Farmers' Union said it was "not in the interests of both consumers and growers to produce food which is not healthy".