A woman, 58, is in critical condition after the taxi she was travelling in hit a power pole at Sylvania on Sunday morning.
Sutherland police say the taxi was travelling south on the Princes Highway at 1.10am when it left the road and hit a pole.
There were three passengers in the taxi at the time.
The woman, 58, who was in the rear passenger side, was trapped.
She was taken to St George Hospital in a critical but stable condition.
Another woman, 29, who was also sitting in the back seat, has been treated for injuries.
The man, 29, sitting in the front passenger seat, was not injured.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000.