Emergency services responded to the fire at Appin about 3pm on Monday where two bodies were found in the aircraft wreckage, NSW Police said.

"Following an extensive search of the area crews located a light plane with two deceased persons," police said in a statement.

A crime scene has been established with police to work with the Australian Transport Safety Bureau to determine the circumstances of the incident.

The two victims are yet to be formally identified.

Appin Road was closed in both directions between the M1 Princes Motorway and Colliery Road at Appin due to the fire.

Australian Associated Press