The man was stopped on the expressway near Cambridge.

A 33-year-old man has been arrested after a routine traffic stop allegedly uncovered about 5kg of cannabis.

Police stopped a vehicle travelling on the expressway on the outskirts of Cambridge about 5.15pm on Thursday, a police statement said.

While they were speaking with the driver, they noticed a strong smell of cannabis coming from the vehicle.

The vehicle was searched and police found 111 bagged ounces of cannabis, as well as four pounds of cannabis heads, which is about 5kg in total.

The man will appear in Hamilton District Court at a later date on drug-related charges.