A DETECTIVE left a man permanently brain damaged when he felled him with a single punch during a stag night out, a court heard yesterday.

Detective Constable John Beresford, 43, lashed out after father-of-three Graeme McMillan sprang to his wife's defence following a lurid comment from the bachelor party, it was alleged.

Newcastle Crown Court heard how Mr McMillan and his 40-year-old wife, Carole, were enjoying a night out on Newcastle's packed Quayside when the incident happened on June 8 last year.

John Evans, prosecuting, told the court how the couple were making their way towards a taxi rank when they heard a voice saying he would like to have sex with Mrs McMillan.

When Mr McMillan told the group they should show some respect, he was punched to the ground and lay on the pavement with blood pouring from his ear.

The court heard how the tool fitter was taken 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.

Det Con Beresford had been out since lunchtime with colleagues from the Durham force celebrating an impending marriage, the court heard.

He admits punching Mr McMillan, but claims he lashed out after someone punched one of his colleagues.

The court heard how the policeman had taken a train from Chester-le-Street into Newcastle for a pub crawl.

After hearing reports on local radio about Mr McMillan's condition next day, Det Con Beresford came forward.

He denies causing grievous bodily harm.

The trial continues.