The bird of prey was discovered near Greenhow in Nidderdale on March 11.
Its carcass was found to contain lead shot.
Red kites are a common sight in the skies above north Leeds and the Harrogate area since they were successfully re-introduced to the Harewood estate in 1999. There are now over 300 of the birds in the region.
Wildlife crime officer PC David Mackay from North Yorkshire Police Rural Taskforce said:
“It has taken many years to re-introduce red kites after their near-extinction from the UK, and these magnificent birds can now regularly be seen in the skies over North Yorkshire.
“They are a Schedule One bird and have special legal protection under the Wildlife and Countryside Act. They feed on carrion and pose no threat to game birds, farmed animals or pets.
“I would ask anyone who has any information that could assist the investigation to get in touch with me.”
In spring 2016, eight red kites were shot or poisoned in a spate of persecutions in North and West Yorkshire.
North Yorkshire Police are being supported in the investigation by Yorkshire Red Kites.
Anyone with information is asked to contact North Yorkshire Police on 101, select option 2 and ask for PC 1452 David Mackay, or email [email protected] You can also contact Crimestoppers anonymously on 0800 555 111. Please quote reference number 12170047155 when passing information.