A policeman filmed punching a shoplifter in the head at a Canterbury department store will not be prosecuted for assault, it's been revealed.

Burly PC Brett Wright, 40, struck Jack Harbour’s face twice, causing him to collapse to the ground in a back room at Debenhams in the city centre last summer.

However, the Crown Prosection Service said it had examined the case and there was not enough evidence “to provide a realistic prospect of conviction” of the officer.

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PC Wright, of Manley Road in Dover, will not be charged with perverting the course of justice, but two other officers involved in Harbour’s arrest will face trial over allegations they lied about the existence of the CCTV footage.

The Wessex division of the CPS looked into the assault case against PC Wright.

Spokesman Marie-Dominique Meunier said: “We carefully reviewed a file of evidence in relation to an allegation that PC Brett Wright had assaulted a member of the public on July 11, 2013.

“The evidence included expert evidence regarding the use of force used and based on that evidence we were not satisfied that there was sufficient evidence to provide a realistic prospect of conviction.

“This decision was made in accordance with the Code for Crown Prosecutors.”

After hearing the officer would not be prosecuted, Harbour’s mother Linda said from her home in the Murston area of Sittingbourne: “I’ve seen the video of what happened in Debenhams lots of times.

“It’s disgusting that the officer hasn’t been charged.”

Harbour, 23, was seen stealing perfume in Debenhams on July 11 last year.

Police were called and took him to a side room. They began to restrain him in the belief that Harbour, who was drunk at the time, was preparing to spit at them.

PC Wright then struck him twice. The four-minute film shows the officers huddled over him for about 50 seconds, before pulling him onto his feet and handcuffing him.

The clip, which was posted on YouTube, ends with Harbour sitting down and the officers standing over him.

Harbour was later convicted of the theft, but a charge of assaulting a police officer was dropped.

Video: Police in confrontation with shoplifter Jack Harbour

Conspiracy to pervert the course of justice cases will proceed against PC Geoffrey Keen, 31, of Byllan Road, Dover, and 37-year-old PC Daniel Short, of Freshwater Close, Herne Bay.

The trio are currently suspended from duty but Kent Police is reviewing PC Wright’s suspension.