As part of Operation Stratum, police from the Heavy Vehicle Unit intercepted a bus in Bonnie Doon yesterday (21 July).
The mini bus was intercepted on Maroondah Highway about 9.30am.
The driver of the bus, a man in his 40s from Clayton, returned an alleged positive test for drugs.
Eight people, including the driver, were on the bus at the time.
The man is expected to be charged on summons with exceed prescribed concentration of drugs, work diary offences and fail to have driver accreditation.
Police from the Heavy Vehicle Unit will continue to target heavy vehicles in Mansfield and the surrounding areas as part of the operation which focuses on vehicles, including buses and trucks heading to the snowfields this season.