A detective who left a man brain damaged when he felled him with a single punch was jailed for 15 months yesterday.

Dad-of-three Graeme McMillan, 44, was sent crashing to the ground when he sprang to the defence of his wife following a comment from a stag night reveller.

Det Const John Beresford and his pals, who had been drinking all day, walked away as Mr McMillan lay on the ground with blood trickling from his left ear.

Mr McMillan's wife Carole broke down in tears as the jury at Newcastle Crown Court found her husband's attacker guilty of grievous bodily harm.

As Beresford, 44, stood impassivelty in the dock the court heard how his brutal attack had destroyed his victim's life.

Judge John Milford said although Beresford was of "exemplary" character, an "excellent family man and citizen who had been a good policeman" the inevitable jail term for such an attack could not be avoided.

He said: "I have no doubt what you did was out of character. Had you been sober it would not have happened, but it did.

"You shattered a man's life and that of his family. You may feel your life is shattered too and in many ways it is.

"But you have your health and the capacity to rebuild your life when you have served your sentence. Mr McMillan has no such option."

As he was sentenced, Beresford's wife Lillian wept in the public gallery.

Newcastle Crown Court had heard how Mr and Mrs McMillan were enjoying a night out on Newcastle's packed Quayside when the tragedy happened on June 8 last year.

Prosecutor John Evans told the court how the couple were making their way towards a taxi rank when they heard a strange voice.

When Mr McMillan told the group they should show some respect, he was punched to the ground.

The court heard how Detective Constable Beresford had been out since lunchtime with colleagues from the Durham force celebrating an impending marriage.

Mr McMillan, of Kingston Park, Newcastle, spent weeks in intensive care in a coma.

Durham Constabulary policeman Beresford, of Chester-le-Street, Co Durham, admitted striking Mr McMillan but said he had hit out in self defence.

Paul Sloan, QC, defending, said: "What happened was not of his making, he did not cause or set out to cause trouble, he reacted to trouble that arose.

"His reaction was instantaneous, it was spontaneous. There was no pre- mediation on his part."