UPDATE 7.15AM: All southbound lanes have now reopened on the M1 Pacific Motorway between West Wallsend and Ryhope after the early-morning fatal crash.
EARLIER REPORT: A motorbike rider has died after coming off his bike on the M1 Pacific Motorway between West Wallsend and Ryhope early Wednesday morning.
Shortly after 1am two motorbikes were travelling southbound at speed when one rider has come off his bike.
He was thrown from the motorbike onto the road before being hit by a car also heading south. 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 said.
Officers from the Crash Investigation Unit are attending to assist Lake Macquarie officers with a full investigation and 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.
Anyone with information about this incident is urged to contact Crime Stoppers: 1800 333 000 or https://nsw.crimestoppers.com.au.
Motorists heading southbound on the M1 near the crash scene are being diverted; motorists are encouraged to check livetraffic.com for the latest traffic updates.
Those travelling southbound are being diverted on to Newcastle Link Road at Cameron Park, Lake Road to Toronto and Awaba Road and Cessnock Road in Ryhope to return to the motorway.
Northbound lanes remain open on the motorway.
Motorists are advised to allow extra travel time and follow directions of emergency services and traffic crews in the area.
There is no forecast of when southbound lanes of the motorway will reopen.
Additionally, one of three northbound and southbound lanes on the M1 are closed at Mount Colah due to a truck crash at Kuringgai Chase Road.
Emergency services and traffic crews are at the site of the crash.
Motorists are advised to exercise caution and reduce your speed through the area.
