People in north Worcestershire are being warned that buying venison under the counter could have fatal results.
The warning was issued after a deer that had been recently injected with tranquilisers was stolen near Kidderminster.
Police said anyone who ate its meat could suffer from breathing problems or even have a heart attack.
The animal was one of 15 that have been stolen from the same place between the beginning of February and 15 March.
Pc Pauline Montague said: "The deer which had been tranquillized had blue dye on it to identify it.
"However, we are concerned that the skin of the animal could have been removed in order for the meat to be sold on.
"We have been informed that the tranquilliser that was used can cause respiratory depression in humans and in the worst case can lead to cardiac failure.
"We are unsure exactly when the deer was stolen and so do not know how toxic the meat could now be, or if it has indeed been sold on."
The police are urging anyone who is offered venison in suspicious circumstances to contact them immediately.