Horsemeat has been found in cottage pies from a supplier that sends food to 47 county schools.
The provisional results of the tests on a pre-prepared cottage pie from an external supplier were reported late yesterday evening, February 14, and have been passed on to the Food Standards Agency.
Lancashire county council has not confirmed which schools are affected but said teachers and parents would be informed.
No Hyndburn schools admitted they are involved, when contacted by the Accrington Observer on Friday afternoon, although several were uncontactable as they were on preparing to start half term.
Of 15 schools surveyed, nine said they were clear, with the rest either not sure, unable to comment or uncontactable.
The products have been withdrawn from all school kitchens.
County Councillor Susie Charles, cabinet member for children and schools, said: "We share the concerns people have about what is
clearly a major problem in food supplies across the UK and Europe.
"Because of those concerns we decided to seek extra assurance that our external suppliers were not providing any products containing horsemeat DNA, and one of the products has returned a positive result.
"Relatively few schools in Lancashire use this particular product but our priority is to provide absolute assurance that meals contain what the label says – having discovered this one doesn't, we have no hesitation in removing it from menus.
"This does not appear to be a food safety issue but I've no doubt parents will agree we need to take a very firm line with suppliers and it is a credit to our officers that we have been able to quickly identify the problem and take the product off the menus."
Since concerns over the contamination of horsemeat arose, Lancashire County Scientific Service has played a key role in the analysis of beef products. Lancashire's is one of 7 laboratories in the UK accredited to carry out the tests that have been requested by the Food Standards Agency.
In response to those concerns the county council's catering service submitted a range of beef products from its suppliers to be analysed by Lancashire County Scientific Services, in accordance with Food Standards Agency guidelines.