Apples, peas, and grapes are sometimes covered in crop spray that is above the maximum allowed levels allowed under European law.

The findings come from the Pesticides Residues Committee, part of the Health and Safety Executive, after testing more than 4,000 samples of food and drink.

The levels of pesticides varied considerably, with imported fruit and vegetables tending to have higher levels, according to its 2008 annual report. One in 7 beans in a pod one in 25 fresh peas (in pods) and one in five yams all had pesticides above the allowed level. One in 70 apples and pears had illegal levels of pesticides.

The Food Standards Agency insisted the illegal levels did not necessarily mean that the food was unsafe to eat, and pointed out that the overall levels of pesticides in food had fallen over the last year. In 2007 1.8 per cent of food had illegal levels; 2008 it had fallen to 1.2 per cent.

All of the fruit and vegetables supplied to schools contained pesticides within allowed levels, though nearly all the apples (49 out of 52 tested) and every one of the bananas had some form of pesticide in them. Many of the pieces of fruit had more than one pesticide.