Police have issued a warning about contaminated meat after sheep were stolen and killed for their meat on the county border with Rutland.
Five sheep have been stolen on two separate occasions from land near Cottingham.
Five of these have been found having been killed, skinned and the meat taken in a manner that was clear they were killed for their meat.
The main concern is the day before the sheep were stolen they were given Noromectin, a drug which is used to treat worms in sheep.
The safety advice is the sheep must not be slaughtered for human consumption until 42 days after the last treatment.
While the risk is not great, the company which produces the drug says it has the potential to cause nausea, vomiting and diarrhoea.
A police spokesman said: “We’d ask the public to be very vigilant of people selling meat in the area, in particular local butchers who might be approached.”
Anyone with information about the sheep thefts can contact Northamptonshire Police on 101 or they can call Crimestoppers anonymously on 0800 555111.