A mechanic who claimed he attacked and killed in self-defence a bomb disposal expert who worked for mine clearing charity supported by Princess Diana has been found guilty of the manslaughter.

Colin Gale (40) claimed, in April 2014, he inflicted the fatal blows on Mark Manning with a wrench in self-defence after telling him he could not repay a £17,000 debt.

Prosecutor Duncan Atkinson QC said Manning (54) was working at P&B Car Sales in Lancing, West Sussex at the time, and was owed the money from the sale of two vehicles.

After Manning was killed Gale and a friend dumped his body a undergrowth where it remained for nearly two years until the Gale and his accomplice were arrested.

Lewes Crown Court heard Manning had turned up at P&B Car Sales garage in Lancing, West Sussex, in April 2014, where he swung at Gale with an axe after he was told he could not pay him.

Gale struck Manning over the head with a three-foot long industrial wrench, and told jurors he "had to finish him off by hitting him more times or he would come back and get him".

Gale told the court he was acting in self-defence.

He said: "Mark was just raging. I was terrified I would get the axe in me. I couldn't tell you what he said to me because, it happened so quickly.

"He was swinging the axe towards me and I said 'Mark what are you doing?'."

"I hit him a couple more times. It was disgusting."

His friend Stewart Robertson, of St Aubyns Road, Portslade, helped him dispose of the body near Crawley, West Sussex.

Gale, of Worthing, West Sussex, lied to police when arrested and told them he gave Manning a lift to the town's train station but was eventually charged after his wife told police he confessed to her.

Manning, of Lancing, worked for the Mines Advisory Group, supported by Princess Diana.

Gale denied murder, but a jury convicted him of the lesser charge of manslaughter. He had admitted preventing the lawful burial of Manning's body at an earlier hearing.

Robertson had denied preventing lawful burial but was convicted of the charge.

Gale and Robertson will be sentenced later this month.