[Article updated Thursday 2.35pm: Gloucestershire Police say the officer is currently not on frontline duties, correcting information the force released previously]
Police chiefs carried out an internal misconduct investigation after a 12-minute video of the clash was recorded by the 26-year-old photographer using a mobile phone and posted on YouTube.
The photographer, who declined to be named, accused the officer of abusive behaviour while trying to photograph a crash scene in Gloucester on 19 November last year.
An 86-year-old woman, who had been knocked down, later died from her injuries.
The photographer was ordered to delete all his images or face arrest.
The policeman threatened to make his day a ‘living hell' and the video appears to show him holding the photographer's camera - a Canon DSLR.
The photographer was accused of obstructing a police officer and claimed that the police cordon had been lifted at the time he took the shots, and that he was on public land.
‘A full misconduct investigation has now been completed and the complaint against this officer has been upheld,' said Gloucestershire Police in a statement released to Amateur Photographer.
‘A written warning has been given to the officer and we apologise unreservedly to the member of the public for the way they were treated.'
Off frontline duties
The force says the officer was 'removed from frontline duties' at the start of the internal probe and 'will now be subject to a personal development plan to ensure this doesn't happen again'.
A spokesman today confirmed to Amateur Photographer that the policeman remains off frontline duties.
The unnamed officer claimed that the road was closed at the time of the incident and that it was a ‘crime scene', according to the YouTube video which has been watched more than 37,000 times.
He said such pictures were off limits because the ‘family of the person who is seriously injured doesn't know yet' and ‘I don't want you putting stuff on the internet'.
However, the Gloucestershire Police statement adds: ‘All officers sign an oath to serve the public with respect to all people and, while we believe our staff uphold this in the vast majority of incidents, clearly in this case the standard of behaviour fell short of what is expected.'
In a statement accompanying the YouTube video, the photographer said: ‘All those involved had gone already, there were no injured people there, no ambulance. I would never take photos of injured people and publicise it.'
'You are lucky I didn't knock you out'
When the photographer accused the officer of swearing at him, the video appears to show the policeman replying: ‘You are lucky I didn't bloody knock you out to be fair.'
Under threat of arrest he said he was forced to give the officer his name and address.
In the end, after the officer reviewed the photos, no images were deleted.
When asked, the photographer declined to tell the officer whether he was a member of the press.
Police guidelines state that officers have no legal power to prevent or restrict what the media record.