A hen harrier who "suddenly disappeared" eight months ago has been found shot dead on a North Yorkshire grouse moor, according to the RSPB.
River, a female bird who had been tagged with a satellite transmitter, gave a final location in November from a roost on the Swinton Estate.
In March, a signal was picked up again confirming the bird was dead, with its body found on Ilton Moor in April.
Police confirmed the bird's body contained two pieces of shot.
The RSPB said River's satellite tag was solar powered, so it is possible the bird's body was "disturbed" and exposed to light, allowing a signal to be reactivated.
Mark Thomas, the charity's head of investigations, said: "We don't know precisely when or where River was shot, or who did it, but clearly she has been the subject of illegal persecution.
"With just a handful of breeding hen harrier pairs left in England, this is a species with everything to lose if the status quo continues."
The charity appealed for anyone with information about this shooting or other incidents connected to birds of prey being killed to come forward.
Amanda Anderson, director of the Moorland Association, of which the Swinton Estate is a member, said the incident had "greatly distressed" staff and management.
She added: "The estate has taken great pride in the work it has been doing to encourage and help hen harriers and this has resulted in successful winter roosting for several harriers and breeding success this spring.
"Our members, across all these incidents, wish to reiterate their condemnation of all forms of wildlife crime."
A study, published in March, found the survival rate of juvenile hen harriers in England was 17%.