The agency has called a halt to fishing in the North and South Minch, the Sound of Jura and fishing grounds off Islay and the Mull of Kintyre, because of a build up of toxins causing ASP.

Director Dr George Paterson said the agency recognised the consequences the ban would have on the scallop fishing industry.

But he said that public safety always had to come first.

The symptoms associated with ASP can include vomiting, diarrhoea, abdominal pains, confusion, memory loss, seizure and coma.

Fishermen angry

However, fishermen who have already endured a nine-month ban have hit back at the agency.

Hugh Allan, of the Mallaig and Northwest Fishermen's Association, said that scallops caught in those grounds this week had been tested by processors and found to be perfectly safe.

He described the ban as a "bureaucratic blunder". The agency's testing procedures took too long and were not as accurate as those carried out by the industry.

It seems absurd ... that the whole industry should suffer when only such a tiny quantity of scallops could pose a potential risk

Struan Stevenson

Mr Allan said fishermen in the area were already "against the wall" and were now having to pay because the agency was on a learning curve.

Amnesic shellfish poisoning is caused by a toxic algal bloom normally associated with warm weather.

The first major outbreak was detected in scallops last July, prompting the Scottish Executive to introduce widescale bans on fishing.

'Absurd' action

The scallop industry claimed that the move had been an over-reaction which cost it around �10m.

The ban was completely lifted in May this year.

In his letter to the commissioner, Mr Stevenson stated: "The scallop fishermen inform me that 97% of scallops marketed in the UK are processed, effectively removing any potentially toxic organs.

"Only around 3% are sold whole in their shells. It seems absurd, therefore, that the whole industry should suffer when only such a tiny quantity of scallops could pose a potential risk."

He said he had no wish to interfere in the process of scientific investigation but called for action to protect the interests of the Scottish scallop industry.