Horse DNA has been found in a frozen burger in a school kitchen in Scotland, making the institution the latest to be affected by the horse meat scandal.
The discovery in the North Lanarkshire school is the result of widespread local authority testing, the BBC reported. Scotland Excel, which provides food supplies for schools, has advised all councils in Scotland to withdraw frozen beef burger products.
A spokesperson for the agency said it was "very concerned" about the discovery, although it is still unknown where the burgers were manufactured.
Rural affairs secretary Richard Lochhead described the incident as "unnacceptable".
"Of the thousands of tests, this is the first positive result in our schools, but it is one too many," he said. "No company should be supplying our schools with food with beef products that contain traces of horse meat."
"It is unacceptable a burger which has tested positive for traces of horsemeat was supplied to a school in North Lanarkshire."
He added North Lanarkshire Council has taken "immediate action" to withdraw the burgers from the school.
The council said samples of frozen mince had been removed from the area's school kitchens and tested for horse DNA, which came back negative. A spokesperson said the council's investigations would be focusing on the frozen burger supplies.
Last week it was revealed horse meat had been found in cottage pies which were delivered to 47 schools in Lancashire. The horse DNA was discovered after testing was carried out on the pies. Lancashire County Council has said it has removed the products from all school kitchens and there did not appear to be a food safety issue.
Horse meat has also been discovered in burgers sold on three college campuses in Northern Ireland, which were provided by catering company Eurest.Suggest a correction