A near-naked man has been arrested after an alleged car-jacking outside a hospital at Werribee overnight.

Police say the man, wearing only underwear, approached a Hoppers Crossing woman, 45, in the car park of a Princes Highway hospital about 5pm.

He allegedly hauled her from the car and started to drive off, but not before she managed to dive into the back seat.

She attempted to stop him as he drove, prompting the alleged thief to crash into multiple parked cars.

Police arrived and arrested the man, 37, shortly afterwards.

The victim sustained minor injuries and was treated at the scene.

A police officer sustained a minor injury during the arrest and was taken to hospital for treatment.

The man is currently in custody assisting police with their enquiries.

Victoria Police spokesperson Adam West told Ross and John they did not typically encourage victims to become involved.

“Keep yourself out of harm’s way and leave the dirty work for us,” he said.

Click PLAY to Victoria Police’s Adam West discuss the incident and exchanges obligatory puns