A MARTIAL arts expert kicked and punched a man to death because he called his girlfriend a 'slag', a jury was told.

John Beckley, 42, denies murdering window cleaner Roy Helm in his flat in St Nicholas Road, Littlemore, last August.

Mr Helm suffered 20 rib fractures, multiple bruising, internal bleeding and a ruptured kidney, the trial at Oxford Crown Court heard yesterday.

Yvonne Coen, prosecuting, told the court Mr Helm was drinking in the flat with his partner Alison Campbell, Beckley and his girlfriend Lynn Cook.

Late in the evening Beckley - who took part in Tae Kwon Do competitions - launched into a violent attack, punching, kicking and stamping on Mr Helm because he insulted Miss Cook, Miss Coen said.

Miss Coen added: "He caused the fatal injuries by using repeated and devastating force as Roy Helm lay defenceless on the floor. After all, he was a martial arts expert. He would know the sort of damage he could do with targeted blows."

Mr Helm lay in the flat for a further 12 hours before Miss Campbell rang paramedics, who found him dead, she added.

Lynn Cook, also known as Lynn Imbriano, was Mr Helm's former partner and the pair had remained friends, Miss Coen said.

Miss Cook said she had been on a 48-hour drinking binge with Beckley before arriving at the flat.

She said: "Roy was really drunk. He went into the kitchen then came staggering out and scooted across the floor and bust his face. He got up and that's when John hit him. Then there was a rain of blows to Roy."

Miss Cook told the jury since her break-up with Mr Helm he had sent horrible text messages, which Beckley had read. Beckley also knew Mr Helm called her a slag and a slut in front of her two young children, Miss Cook added.

She added: "He (Beckley) kicked him as well. He kept saying 'say sorry to Lynn'. Roy kept saying 'sorry John'. In the end he lifted up his head by his hair and put it next to my face and said 'say sorry to Lynn."

Miss Coen asked Miss Cook to describe a kick to the body. She replied: "It was a hard kick like the way you would kick a football. Roy kept saying 'sorry John, that's enough'."

The blows ended and Mr Helm crawled into the hallway, the jury heard.

The next morning Miss Campbell went to the shop while Mr Helm lay on the bedroom floor, Miss Cook told the jury. She said they left Mr Helm alone because they believed he was sleeping off his hangover.

The couple then cleaned up the blood and left to go to a pub in Cowley. She said: "As much as it sickens me now, me and John had sex on the sofa."

Miss Cook said: "I said to Beck (Beckley) I think Roy could press charges because of the bruises. He said there won't be any bruises because I kept hitting him in the vital organs.

"I said how do you know and he started going on about the Tae Kwon Do thing."

A post-mortem examination showed Mr Helm died from chest and abdominal injuries.

Beckley, who the court records show lived in Kidlington Road, Islip, denies murder.