Traffic across Melbourne was in disarray early on Thursday after police discovered a truck driver who was feared to have an explosive device strapped to his head.

The flow-on effects of the stand off between the 35-year-old prime mover driver and police were felt across the city and into peak hour as officers tried to negotiate with the man after he sped off down the wrong side of the Monash Freeway.

The drama unfolded just after 4am when police were called to the inbound lanes of the freeway after reports that a truck had broken down.

Police said that when they arrived, there appeared to be a suspicious device strapped to the driver’s head.