A police horse may have been spooked by a drone before his death, West Yorkshire Police have said.
Fimber, 14, died after an incident at Carr Gate police headquarters near Wakefield on 15 October.
CCTV footage showed the horse, who had been with the force for 11 years, looking "spooked" in the paddock before vaulting a fence and colliding with a wooden post.
Police have appealed to the owner of a drone found nearby to come forward.
Officers are now investigating the possibility that Fimber's death was linked to a radio-controlled drone found nearby a few days later by the crew of a police helicopter as it came in to land.