A police officer who punched a “violent and disruptive” domestic abuse suspect four times acted legitimately, a disciplinary panel has ruled.

Custody sergeant Paul Coughlan, 52, delivered the blows to Reece Cannon at Canterbury police station during a struggle to get the aggressive 26-year-old to put his arm back into his cell.

Cannon, who had been been arrested on suspicion of punching, biting, strangling and head-butting his girlfriend, lashed out when he asked for water and thought he was told in response to drink from the toilet.

PS Coughlan, who had opened the cell door hatch to give the detainee a cup of water and a jumper, had in fact told him he could use a button tap next to his toilet if he wanted more to drink.

He told an employment tribunal on Monday that as Cannon reached out through the hatch, his abusive manner made him fear for his personal safety, leading him to try to force his arm back in by hitting him on the bicep with with four “hammer fist” punches.

“I thought he was going to be able to get hold of me and injure me,” he said.

“I was struggling with his arm, so I decided that the best thing to do was to weaken his arm so he couldn’t assault me, and so I could push his arm back into the cell.”

Cannon was arrested after biting and throttling his girlfriend in a brutal attack on her birthday.

He was later convicted of assault, and in August, cried out to his mum in the public gallery of Canterbury Crown Court as he was jailed for 35 months.

The panel heard he had arrived at the police station intoxicated the night before the incident with PS Coughlan on March 29, 2017.

He filed a complaint about PS Coughlan's behaviour to the Independent Office of Police Conduct which led to the officer being convicted of assault at Maidstone Magistrates’ Court in April.

However this was later overturned on appeal by the Crown Court, which said it could not be sure the use of force was unreasonable.

Defending counsel Kevin Baumber described PS Coughlan as a “thoughtful” officer who others turned to for advice, and said he had made “an honest and good faith judgement about what to do” in difficult circumstances.

“We can infer from the way that Mr Cannon behaved that a verbal request to put his hand back in would not have worked,” he continued.

“There is a clear absence of injury here. There was a legitimate end being sought, which was the removal of the arm from the hatch, so that the hatch could be closed.

“He knew he was dealing with a man who posed a risk of disruption, a detainee arrested for grievous bodily harm with intent, who was aggressive and lashing out.”

A panel heard how it took five officers to eventually get Cannon’s arm back into the cell and how he had been causing disruption when PS Coughlan arrived for his 7am shift by repeatedly banging on his door and attempting to talk to another detainee.

Reaching the conclusion that no misconduct had taken place, the panel said in a judgement: “We are satisfied that PS Coughlan reasonably feared being grabbed or otherwise assaulted by Mr Cannon and that he did what he honestly and instinctively thought was necessary for a legitimate purpose.”

Speaking after the hearing, Kent Police Federation representative Nick Greenan said: “It’s important that the public see that police conduct is properly monitored and promptly dealt with when complaints are raised.

“The outcome today is in accordance with the earlier appeal outcome.

“The officer - whose career was on the line - is very relieved.”