The first evidence of horse meat in burgers in a school kitchen has been found.
As a result, thousands of burgers have been removed from schools in Scotland after one frozen burger was found to contain horse DNA.
North Lanarkshire Council decided to make the costly move while investigations are carried out to establish if any more burgers contain horse meat.
It's not known whether any pupils had eaten the contaminated burgers.
A council spokesman said: "We notified the Food Standards Agency, as we are required to do, and investigations are continuing.
"In the meantime, stocks of burger products have been removed from North Lanarkshire school kitchens as a precaution."
It is the first such discovery following widespread local authority testing resulting from the discovery of horsemeat in the UK food chain.
Rural Affairs Secretary Richard Lochhead said: "It is unacceptable that a burger which has tested positive for traces of horsemeat was supplied to a school in North Lanarkshire.
"However, North Lanarkshire Council have taken immediate action to withdraw the product from the schools and, as a precautionary measure, all Scottish schools have been advised to put a hold on the use of frozen burgers.
"Of the thousands of tests, this is the first positive result in our schools, but it is one too many. No company should be supplying our schools with food with beef products that contain traces of horse meat."
It is not known who manufactured the North Lanarkshire burger, but a supplier that discovered horse DNA in one of its products elsewhere said no horsemeat has been found in meals it supplies to Scottish schools.