A PRANKSTER was handed a suspended sentence when a colleague was left with serious burns after a practical joke went horribly wrong, a court heard.

Halford's mechanic Adam Clarke had suggested fellow worker Alexandru Petre burst a balloon to scare their boss at the Bicester branch last September.

But unbeknown to Mr Petre, Clarke had filled the balloon with acetylene – a highly flammable gas – and told him to use a lighter to burst it as it would make a bigger bang.

Oxford Crown Court heard on Friday how Mr Petre popped the balloon resulting in an explosion so large it blew a nearby car's doors shut – with their boss inside – and caused severe burns to Mr Petre.

Prosecutor Alexandra Bull said: "The explosion burnt his clothes from his forearms and caused a number of injuries and significant pain."

Staff at the Halfords in Telford Road heard the explosion and saw flames and black smoke coming from the area.

Clarke was arrested and said he had put the flammable gas in the party balloon as a practical joke.

Ms Bull said the 32-year-old told police he thought the explosion would be smaller and added: "He described the balloon bursting as 'like a fireball'.

"He said he knew it would catch fire but thought it would be a small fire."

The court heard Mr Petre was taken to the Stoke Mandeville Hospital in Aylesbury to be treated for burns to his arms, hands and face.

Clarke, of Kestrel Way, Bicester, admitted unlawfully wounding Mr Petre on the afternoon of Thursday, September 10, last year.

Claire Fraser, defending, said her client had shown remorse and had remained friends with Mr Petre after the incident.

She added: "There was no criminal intent from the beginning.

"It was a practical joke that went very wrong and had dire consequences."

The court heard Clarke had lost his job at Halfords and got a new one at another mechanics.

Judge Patrick Eccles QC said despite not intending to cause the injuries, Clarke had been reckless and stupid in playing the prank on his colleague.

He added: "It really was an astonishingly reckless act. It had no sensible purpose.

"It was an act of utter stupidity as well as recklessness."

But Judge Eccles accepted Clarke had not intended to cause Mr Petre harm, although he said it was sheer luck the injuries had not been worse than they were.

Clarke was handed a nine-month prison sentence suspended for a year and ordered to carry out 150 hours' unpaid work, a 10-day rehabilitation activity requirement and pay £2,000 in compensation.