The bird of prey was discovered by a member of the public near the Monadhliath mountains south of Inverness last month.
Police said today that an examination of the buzzard suggests that it did not die of natural causes.
Wildlife crime officers have launched an investigation into the bird's death and have appealed for information.
It was found near the village of Tomatin on December 9.
A Police Scotland spokesman, said: "Anyone who lives nearby or may have frequented the area during outdoor pursuits activities and may have information regarding this crime or any offences against birds of prey is asked to contact police on 101 or Crimestoppers on 0800 555 111."
A golden eagle was found dead in the hills above Glen Lethnot in Angus last month.
Tests on the ringed bird recovered from a moor revealed it had been poisoned.
RSPB Scotland was alerted to the eagle's death when its satellite tracking signal remained static for several days.
In the past five-and-a-half years, another four eagles, a red kite and seven buzzards have been shot, poisoned or trapped on sporting estates in the Angus glens, according to the conservation charity.
Police have asked anyone who was in Glen Lethnot and the surrounding areas between November 10 and 25 to contact them.