Schools in Brighton and Hove have been sent a warning about the horse meat scandal by the Department for Education.
The email included a link to a report by the Food Standards Agency which named five companies so far found to have sold or supplied horse meat.
The five named were Aldi, Co-op, Findus, Rangeland and Tesco.
The email said: “There have been reports today that horsemeat has been found in processed beef products supplied to some schools.
“This follows the publication by the Food Standards Agency (FSA) of test reports received from meat processors and suppliers.
“While advice from the FSA suggests that there is no public health risk associated with this contamination, it constitutes a serious breach of consumer trust.
“Schools and local authorities will share the department’s concern and may wish to let parents and pupils know about any action they are taking.
“We are working closely with the FSA and other government departments as the FSA’s investigation continues.”