A 76-year-old woman and her 51-year-old son, both from Newnham, died in the crash near Ross on Thursday.

Their green 1992 Ford Falcon sedan veered onto the wrong side of the road and collided with a log truck.

The driver of the truck - a 64-year-old man from New Norfolk - was not injured.

Northern Crash Investigation Services are calling for witnesses who saw the Ford before the crash.

Anyone with any information is asking to contact Senior Constable Michael Rybkaor First Class Constable Nigel Housego on 6336 3936 or 6336 3701.