ONE of the staple festive treats has been dropped by the major supermarket chains over health fears.

The European Commission has branded Brazil nuts in their shells a health risk, after traces of a toxin linked to liver cancer was found on the shells.

While the nuts can still be imported in their shells, the EU ruling means they must be inspected and tested for aflatoxins.

Any batches that register more than four parts per billion must be destroyed.

The expense of this operation has forced most retailers to switch to bringing in only the kernels - the edible part of the nut.

Peter Morgan, chairman of the Combined Edible Nut Trade Association, said: "Commercially, it is now too risky to import them.

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

Tesco, Sainsbury's, Asda and WM Morrison are not stocking nuts in shells, but are still offering the packaged kernels.

However, these must be kept refrigerated in sealed containers and have a shorter shelf life than brazils in their shells.

A spokeswoman for Asda said: "If you ask for Brazil nuts in a shell at Christmas, Santa won't be able to deliver.

"However, if you are nuts about Brazils, there are plenty of the shelled variety."

The Foods Standards Agency said that aflatoxins were formed by certain moulds on food, particularly nuts that are grown in warm, humid conditions.

They have been shown to cause cancer in a number of animal species by damaging DNA and there is also evidence to suggest they may cause cancer in humans.

This year's wetter than usual weather led to more nuts going mouldy before they could be harvested.