The horsemeat scandal has prompted the Food Standards Agency to ask a number of local authorities to carry out random tests.
Staffordshire County Council have already removed all processed beef from their school menus.
Trading Standards officers in Leicestershire have now found traces of pork in beef products taken from supermarkets and takeaways.
Jane Hesketh reports.
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Overcast and dull, with hill fog and outbreaks of rain throughout the day.
It will be a dull, damp and cloudy day for most, with outbreaks of rain. The rain will start to ease from the west during the evening.
Cloudy this evening and overnight, with mist and hill fog becoming widespread.