A man fell six storeys from an apartment building in Luton when police approached his flat to arrest him on suspicion of burglary.
The man is in hospital with head and back injuries and a broken leg after the fall from the Startpoint building in Downs Road on Friday morning.
Police said the man appeared to fall while trying to climb from a window.
The Independent Police Complaints Commission has been given details as a matter of routine, a spokesman said.
Officers forced entry into the flat and once inside found the man on the ground outside the building.
They administered first aid before he was taken to hospital by ambulance.
A firearm, suspected drugs and a large quantity of cash were seized during a search of the flat.