POLICE seized what they believe to be about 120 kilograms of cocaine after intercepting an unregistered truck in Wallan yesterday.

Police pulled the truck over as it headed north on the Hume Freeway at about 8am when police identified that its New South Wales registration was expired.

Police searched the truck and located frozen chickens an 12 boxes of a white powder.

The substance was still being forensically tested yesterday evening, but police believe it is cocaine.

Police seized the vehicle, along with the chickens and suspected cocaine.

The driver of the truck, a 23-year-old man from Narre Warren South, is in police custody.

An investigation, which will be headed by Victoria Police Crime Command, is ongoing.

Anyone with information about illicit drug activity is urged to contact Crime Stoppers on 1800 333 000 or make a confidential report at www.crimestoppersvic.com.au.