UPDATE: A man has died and a woman critically injured following a crash near Macksville.
About 6.20am, police and emergency services were called after a south bound Ford Falcon crossed onto the incorrect side of the road and collided with a Nissan travelling north bound.
The male driver of the Ford - believed to be aged 50 - was taken by ambulance paramedics to Coffs Harbour Health Campus in a critical condition but could not be revived.
The 59-year-old female driver of the Nissan was flown by Westac Lifesaver helicopter to John Hunter Hospital where she is believed to be in a critical condition,
Police from Mid North Coast Local Area Command are investigating.
Anyone with information that may assist is asked to call Crime Stoppers on 1800 333 000.
12.20pm UPDATE: Motorists report the highway has been cleared and traffic is again flowing.
However, official confirmation is still to be received.
Police media is expected to release a statement later in the day.
Highway closed south of Macksville
THE PACIFIC Highway remains closed south of Macksville due to a serious two car traffic incident near Warrell Creek Road.
Motorists are being diverted off the highway via Upper Warrell Road.
This diversions is not suitable for heavy vehicles.
Heavy vehicles are advised to use the New England Highway.
Due to the nature of the incident the highway is expected to be closed for some time.
Emergency services, traffic crews and police investigators are attending the scene.
For the latest traffic information, visit livetraffic.com or call 132 701.