Drone footage is being sought in the investigation into the death of a man at a castle.
Charlie Hilder, 66, died at Lullingstone Castle in Eynsford, Kent, on Thursday after officers were called to reports of "rocks being thrown".
The 66-year-old may have been confronting poachers shortly before his death, an angling society has said.
Officers believe a drone in the area at the time could have captured "important video footage".
"We would like to trace the owner to identify whether it recorded any images," Det Ch Insp Gavin Moss said.
Officers called to a disturbance within the castle grounds said they believed the man may have been in an altercation with two boys or teenagers near a lake, before his death.
People should contact police if they witnessed the altercation or "saw two young people in the vicinity of the lake" between 12:00 BST and 19:00, Det Ch Insp Moss said.
"One of them may have been carrying a fishing rod," he said.
The castle is owned by Tom Hart Dyke, cousin of comedy actor Miranda Hart and the property has been closed due to the Covid-19 pandemic.