PHNOM PENH - A French garage owner who polished off a bottle of whisky before robbing his local bank in Cambodia at gunpoint was jailed for six years on Wednesday.

Francois Chateau, 48, was handed the prison sentence for bank robbery and illegal possession of a gun by a Phnom Penh court, after he was nabbed by police after stealing 300 dollars.

Chateau criticised the court's decision, saying his judgment was impaired by drink at the time of the robbery near his car garage in February this year.

"It was unfair because I was completely drunk after finishing a bottle of whisky," he told reporters.

"I very much regret my mistake," he added.

During his trial last month, the court heard Chateau went into the bank and demanded money before laying down the gun on the counter and crashing into a glass door on his way out - he was arrested by police outside.

His lawyer Dun Vibol told AFP that Chateau would appeal the court's ruling to seek a reduction in his jail term on the grounds that he suffers from mental health problems.

Chateau committed the robbery because he was disappointed with his parents who did not phone him on his birthday, Dun Vibol said.

He is believed to have received the Glock pistol in lieu of payment for car repairs from a customer.