Peregrine falcons are protected by law

A falconer contacted the police after finding the bird in his garden, smeared with a toxic pesticide.

Officers then attached a radio transmitter to the pigeon and tracked its flight home.

The bird, codenamed Speckled Jim, led officers to a house in Ashburton, but it proved to be the wrong address.

That stuff is so toxic we would now be talking about a dead child Insp Nevin Hunter

It is believed to be the first time a UK police force has used a homing device to try to track down a poisoner in this way.

Police had hoped to send Speckled Jim out again a few weeks later but before they could, the pigeon died from the effects of the poison.

Speckled Jim was discovered on 23 June close to a peregrine falcon nest containing two young chicks abandoned by their parents, which officers believe were poisoned.

A day earlier a dead peregrine was found on top of a dead pigeon at a breeding site less than five miles away, near Buckfastleigh.

Officers believe that pigeon fanciers, whose birds are sometimes killed by falcons, are behind the illegal poisonings.

Inspector Nevin Hunter, a wildlife liaison officer with Devon and Cornwall Police, said: "Our suspicions are that the person doing this lives within four or five miles of that area."

Recent survey

Police have records of peregrine falcons around Ashburton being poisoned with the same pesticide, aldicarb, since 1994.

Insp Hunter said: "We want people to tell us who's doing it because it's not doing the reputation of other pigeon fanciers any good.

"If we had ended up with a child picking it up, that stuff is so toxic we would now be talking about a dead child."