Scotland's councils have been told not to use any frozen beef products after a burger was found to contain traces of horse DNA.
The advice comes after local authorities were earlier advised to "place a hold" on frozen beef burgers following the discovery in a burger at a North Lanarkshire school kitchen.
It means schools, council leisure facilities and some social care establishments have also been told not to use any current stocks they have of frozen beef products, including mince.
They were also advised not to order any new stocks until the outcome of detailed investigations. The move was confirmed by procurement agency Scotland Excel, which deals with contracts on a national basis.
It recommended councils and other public-sector customers to take a "precautionary approach" and take all frozen beef products off the menu.
Scotland Excel also said one of its suppliers, the food group Brakes, has placed an immediate hold on its beef burgers as a precautionary measure.
A spokesman for Brakes confirmed: "On February 21 we were informed by the Food Standards Agency (FSA) that a frozen beef burger had tested positive for horse DNA following a sample taken from a local authority school in Scotland.
"Before this incident, Brakes has already received negative test results on all 127 beef products supplied to that customer.
"In addition, Brakes had received 32 negative tests results on products that we buy from the same supplier and they, in turn, had 28 negative tests on finished products and raw material they handle. We have a duty of care to all our customers. Until we are able to ascertain the facts, we have placed the beef burger on hold as a precaution.
"All customers are currently being contacted to ensure they hold the product in a segregated area while we, and the FSA, continue investigations. We apologise for any inconvenience this may cause."