Two products have been withdrawn from supermarket shelves because they have been found to contain a banned dye.
The Para Red dye is similar to Sudan I
Para Red, which may cause cancer, was found in paprika and rice cakes.
All Bart Spices jars of paprika have been pulled from supermarkets including Waitrose and Somerfield, along with packs sold under the Co-op label.
Tesco has recalled batches of own-brand barbecue flavoured rice cakes, which contained Para Red and another banned dye which has caused alarm, Sudan I.
The Food Standards Agency (FSA) says Para Red is chemically similar to Sudan I, a genotoxic carcinogen that in February was found to have contaminated a batch of Worcester Sauce, causing the recall of hundreds of products.
The FSA says its independent scientific experts have advised that while there is very limited data available about Para Red, "it would be prudent to assume that it could be a genotoxic carcinogen".
The FSA says the risk to people's health from Para Red is likely to be very small, but is advising consumers not to eat a product containing the dye.
A spokeswoman for the FSA said the latest finds were part of the agency's continuing investigations following the discovery of the dye last week in some batches of the seasoning mix in Old El Paso Dinner Kits.
"The original alert came from the discovery of the Para Red in ingredients of El Paso products, and this latest alert is a follow-up from that," she said.
She said the agency was working with the European Commission and individual EU member states to see if any other products may have been contaminated.
"In the end it is the legal responsibility of the company that sells a product on to the public to ensure that the product is safe," she said.
Investigations had found that "Para Red has entered the UK from other member states", she said, but refused to name which countries.
The FSA says the Bart products which were contaminated were Bart Ground Paprika in 48g glass jars, batch codes 5032 and 5089, with best-before-end dates of December 2007.
Bart also supplies ground paprika to Co-op, which has withdrawn all 46g jars of ground paprika, with batch code 5075 and best-before-end dates of February 2007.
A spokesman for Bart said: "As a company committed to supplying only the very finest quality food ingredients, we took the immediate decision to withdraw our ground paprika spice from all outlets selling the product and advertised a product recall in the national press."
Co-op has issued general notices on the shelves where the product is normally sold.
Tesco has withdrawn all batches of its own brand 130g barbecue flavoured rice cakes with best-before-end dates of November and December 2005.