From Victoria Police

Police are appealing for witnesses following a collision at Longwarry last night.

Police have been told that, prior to the collision, the driver of a green Nissan Pulsar, registered OUL 866, was seen driving erratically on the Princes Highway at approximately 5.45pm.

A short time later the Nissan was involved in a high-speed collision with another vehicle on the highway at Longwarry.

The driver of the Nissan failed to stop at the crash scene and continued driving towards Warragul until he was intercepted by police.

Investigators would like to speak to anyone who may have seen the vehicle being driven in an easterly direction on the highway in the Bunyip or Garfield areas prior to the crash.

The Pakenham man is in hospital in a serious condition and police are appealing for anyone with information or dash-cam footage to contact Crime Stoppers on 1800 333 000 or file a confidential report at www.crimestoppersvic.com.au