Man's body found in car in Blue Mountains

A man's body has been found inside a car in the NSW Blue Mountains.

Police were called to Yileena Avenue, Lawson, about 3am on Tuesday after a man's body was found inside the car parked on the street.

The man, believed to be in his 40s, is yet to be formally identified.

Blue Mountains police have established a crime scene and are treating the death as suspicious.