A former Perth police officer has been sentenced to 14 months jail for stealing $57,000 from a northern suburbs police station.

Robert John Talbot Lawrence was working at the Mirrabooka station when he stole the money from a secure unit between May and July last year.

The money had either been seized from criminals or was payment for outstanding fines.

The District Court was told Lawrence was a compulsive gambler and stole the money to pay debts.

The court also heard he had paid back more than half the money.

Lawrence will have to serve seven months before he can be released.