Man comes off bike, hit and killed by car

A motorcyclist has died after he came off his bike and was hit by a car in NSW's Lake Macquarie area with police looking for his companion, who left the scene.

Police were told two motorbikes were on the M1 between West Wallsend and Ryhope shortly after 1am on Wednesday when one of the riders was thrown from his bike on to the road. He was then struck by a car travelling behind him.

The rider died at the scene. The female driver of the vehicle was taken to John Hunter Hospital for mandatory tests.

The rider of the second motorbike did not stop. Police are calling for any witnesses, or anyone who may have dash-cam vision of the two motorbikes just prior to the crash, to come forward.

Motorists heading southbound on the M1 are being told to check for the latest traffic updates as diversions are in place.