Officers from Sommerville Highway Patrol impounded a less than roadworthy tow truck in Carrum Downs early this morning.
Members were patrolling Hall Road about 12.30am when they noticed the truck, with only one working light, travelling through a roundabout and having trouble slowing.
They intercepted the truck and noted that it was in quite poor condition with bald tyres, leaking brake fluid and a number of other defects.
Police spoke to the driver, a 26-year-old man from Clyde, who underwent a preliminary oral fluid test which indicated a positive result.
Officers will await test results but he was also interviewed for disqualified driving and other traffic offences.
The truck was impounded with towing costs of $1006 and the driver is expected to be charged on summons.