A decorator is suing after three of his fingers were chopped off in a police cell door.
Footage of the horrific moment Jamie Clark had his hand shut in the door at Dyfed Powys police station was caught on camera.
The 28-year-old had been wrongly accused of assaulting a police officer.
Self-employed painter Jamie was later cleared of the assault - and has now won a legal fight to get the footage of the excruciating moment his fingers were severed.
He has passed it on to the police complaints watchdog IPCC in a formal complaint over his treatment.
Dad-of-one Jamie told how he was arrested after a row with his girlfriend - which ended with him being disabled for life.
He was accused of attempting to assault PC Christopher Burton following his arrest in June in Llanelli, West Wales.
Magistrates heard Jamie tried to bite PC Burton while he and other officers attempted to get him into a police van.
But he was cleared in court after his solicitor fought to obtain a copy of the CCTV from police.
The video shows him naked running at the cell door as it was being closed.
PC Burton found a piece of the his finger in the hall, the court heard.
Jamie, of Burry Port, Carmarthenshire, is now suing police for the loss of his fingers.
His solicitor Patrick Llewelyn said: "He was arrested for an offence he wasn't prosecuted for, and while being detained he suffered serious injuries which will be the subject of a complaint or civil claim.
"People expect to be treated fairly when they are dealing with the police.
"We have seen evidence which suggests the police, on this occasion, deviated from the highest standards of practice."
A Dyfed-Powys Police spokeswoman said: "We can confirm an incident occurred on the night of Monday, June 20, whereby a male required hospital treatment after suffering an injury while in custody.
"The matter has been referred to the Independent Police Complaints Commission. It would be inappropriate to comment further at this time."
A spokesman for the IPCC said: "We are independently investigating how a man sustained a serious hand injury in custody in Llanelli on 20 June.
"Investigators have reviewed CCTV footage and are assessing statements from officers. The IPCC investigation follows a referral from Dyfed Powys Police and is ongoing."