Paralysis fear over shellfish.
SCOTTISH mussels bought at Tesco, Asda and Morrisons have tested positive for potentially deadly toxins.
Customers have been warned not to eat any that were sold in 1kg bags between September 4 and 6.
Scientists say the contents - supplied by the Scottish Shellfish Marketing Group (SSMG) - may contain illegally high levels of the toxin which causes paralytic shellfish poisoning.
Symptoms come on rapidly, from a tingling in the mouth that spreads through the body.
This soon turns to numbness and, in extreme cases, can lead to paralysis which stops the sufferer breathing.
So far no one is known to have fallen ill but the Food Standards Agency are not taking any chances.
A spokeswoman for the FSA said last night: "Under no circumstances should they be eaten.
"The mussels should be disposed of or returned to the stores for a refund."
Lanarkshire-based SSMG's stock is farmed from sheltered sea lochs along the west coast of Scotland, from Kintyre to the Shetlands.
They supply mussels, oysters and scallops to wholesalers, supermarkets and restaurants throughout the country.
Asda sold 110 bags, priced at pounds 3.28 each, at 50 of their fresh fish counters on September 6.
A spokesman for the supermarket said yesterday: "We have received no customer complaints.
"Even though the mussels will have passed their use-by-date, in the unlikely event that they're still in your fridge, bring them back to Asda and we will give you your money back."
A Tesco spokesman said: "We take this issue very seriously,
"As soon as we were alerted about a potential problem by our supplier, we removed all mussels from our shelves as a precautionary measure."
SSMG, who provided shellfish for the Queen's 80th birthday party, said: "This is an isolated batch."
They added that it was highly unusual and that they test their shellfish.
SUPPLIER: Scottish Shellfish Marketing Group