CCTV footage that appeared to show police officers repeatedly punching a stab victim is being investigated.
Darren Grace, 31, claims he was assaulted by one female and two male officers as he was being treated for knife wounds in a Liverpool park last August. The CCTV footage appears to show a half-naked Mr Grace bleeding heavily and resisting the Merseyside Police officers' attempts to treat his wounds.
During the four-minute recording, he appears to be punched several times in the head by a male police officer and hit in the body by the female PC and another male constable.
Merseyside Police said last night that CCTV images "can never show the whole story", adding that its professional standards unit was investigating the matter.
Mr Grace was held at a police station for 11 hours following the alleged incident. Charges brought against him of assaulting the police officers were later dropped by the Crown Prosecution Service.