'Serious' overnight crash shuts highway, police investigation launched

One car reportedly hit a tree just after midnight on the Castlereagh Highway, south of Mudgee.

A 22-year-old man was airlifted to Westmead Hospital in Sydney. A second passenger was treated at the scene.

It remains unclear what caused the crash. The highway remains closed in both directions.

"Ongoing police investigations are expected to take some time," a LiveTraffic notice says.

"Use diversions, allow extra travel time and plan your journey."

Detours through Wellington will likely add about 35 minutes when travelling south to Orange.

The Central Western Daily has contacted NSW Police for further information. This story will be updated when it becomes available.

The crash site is in the Burrundulla area, near the Melrose Road intersection.

Ambulances, fire fighters, police and the crash investigation unit were called to the scene.

North- and south-bound detours have been set up.