A DETECTIVE who left a man brain-damaged when he felled him with a single punch has been jailed for 15 months.

Father-of-three Graeme McMillan, 44, was sent crashing to the ground when he sprang to the defence of his wife following a lewd comment from a stag night reveller on Newcastle's Quayside.

DC 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 found her husband's attacker guilty on Wednesday.

Beresford, 44, who lives in Chester-le-Street and is based in Consett, stood impassively in the dock as the court heard how his brutal attack had destroyed his victim's life.

In a statement to the court Mrs McMillan, 40, said: "The Graeme I knew and loved died that night and I was left with a total stranger in Graeme's body."

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.

Judge Milford 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.

The court heard how Mr McMillan, a tool fitter of Kingston Park, Newcastle, was rushed to Newcastle General Hospital's high dependency unit where his condition deteriorated so badly that part of his brain had to be removed. He has been left permanently brain damaged and the couple have been forced to separate for the safety of their children because of Mr McMillan's now bizarre behaviour.

Beresford admitted striking Mr McMillan in the incident on June 8 last year but claimed he had hit out in self-defence. The jury found him guilty of grievous bodily harm on a majority verdict after more than three hours of deliberations.

Paul Sloan QC, defending, said Beresford lashed out after Mr McMillan punched groom Stephen Day in reaction to the comment about his wife.

Mr Sloan said: "His reaction was instantaneous."