A pursuit involving a man who died was terminated before his vehicle slammed into a tree in the NSW Blue Mountains, police say.
The 35-year-old failed to stop at a roadside breath test on the Great Western Highway at Lapstone about 10.10pm on Saturday.
He was pursued by officers through the area before re-entering the highway and police terminated the chase, Assistant Commissioner Mark Jones said.
"A short time later it's believed the vehicle has collided with the median strip and then a tree," he told reporters outside Sutherland police station on Sunday.
The force of the impact split the vehicle in two.
"The driver remained within the cabin of the vehicle where police found him at the location," Mr Jones said.
The man was taken to Nepean Hospital where he was pronounced dead.
Mr Jones said officers had no choice but to act when the man fled the breath test.
NSW Premier Gladys Berejiklian said she was yet to receive all the details on the crash.
"But it's always a tragedy when anybody dies under those circumstances," she said on Sunday.
A critical incident team will investigate the crash.
