British supermarkets are still stocking Brazil kernels

The European Commission has branded the nuts a health risk after traces of a toxin that can cause liver cancer were found in Brazil nut shells.

Each batch must now be tested for aflatoxins, and the cost of destroying those affected has made Brazils too costly for supermarkets to import.

It is still possible to buy just the kernels, as used in chocolate Brazils.

A spokeswoman for Sainsbury's said: "Like other retailers, we don't stock shelled Brazil nuts due to EU regulations. However, we have plenty of unshelled Brazil nuts in stock."

Brazil is the only country to export the nuts still in their shells. Kernels, which are just the edible part of the nut, are brought in from Peru and Bolivia.

'Too risky'

Peter Morgan, chairman of the Combined Edible Nut Trade Association, told the Daily Mail on Friday: "Commercially it is now too risky to import them.

"The EU have put overly stringent limits on this without really good evidence."

The European limit on aflatoxin levels in Brazil nuts is four parts per billion but Mr Morgan said the American limit is 15 parts per billion.

EC officials say levels 100 times higher than the limit have been found.