A £1000 reward is being offered after a red kite was found poisoned in the Tadcaster area.
Police and the RSPB have this week issued an appeal for information surrounding the death of the protected bird of prey found at Toulston Polo Ground in October 2012.
Following a post mortem examination and lengthy forensic testing, it was found to have died from the illegal poison carbofuran, which was banned in 2001.
PC Sarah Ward, of Tadcaster Safer Neighbourhood Team, said: “This crime is appalling.
“The use of carbofuran is both unlawful and highly dangerous.
“It is highly toxic and a few granules could kill.
“Someone has put carbofuran into the countryside unlawfully, risking the lives of people, domesticated animals and wildlife.
“I urge anyone with information to contact the police or RSPB immediately.”
The red kite which died was hatched in Wales in 2009 and is believed to be one of a breeding pair, which first bred at Tadcaster Grammar School in 2012.
They are the first-known Welsh born red kites to have bred in Yorkshire.
Between 2002 and 2011, there were 292 confirmed cases of birds of prey being killed by carbofuran poisoning in England.
Bob Elliot, RSPB Head of Investigations said: “Since their successful release back into the Yorkshire countryside in 1999, red kites have suffered at the hands of illegal poisoning in North Yorkshire with this incident being the twentieth poisoned Kite since 2000.”
The RSPB have offered a £1,000 reward for anyone who can provide information that leads to the arrest and charging of those responsible for the bird’s death.
Mr Elliot added: “Birds of prey are still being targeted by those intent on killing our most protected species and it is simply not acceptable to still be finding poisoned, trapped and shot raptors in our countryside.”
Anyone with information on the poisoning should contact Tadcaster police on 101, select option 2 and ask for Sarah Ward.