Two males have died in a crash after being pursued by highway patrol police officers in Sydney's inner west.
Police allege the driver of a silver Audi was speeding and failed to stop when officers attempted to pull it over, just before 12:30am near Centenary Drive, Strathfield.
A police chase ensued for about two kilometres before the car crashed into a railing on the southbound ramp to the M4 motorway at Homebush.
The car travelled through bush before landing upside down and bursting into flames.
Acting Assistant Commissioner Adam Whyte said the driver was travelling at "excessive" speed, but did not specify exactly what that was.
"The speed did not change. It continued to be excessive. The speed itself will be part of the investigation," he said.
"It's amazing that no other vehicles were impacted."
Several drivers stopped to try and help get the occupants out of the car, including another vehicle carrying an off-duty officer and two policing students, but they were unable to help due to the fire.
Once Fire and Rescue NSW had extinguished the blaze, two bodies were found inside.
The crash has caused road closures and extensive delays in the area.
Police are attempting to identify the bodies, and a critical investigation has been launched to understand the circumstances of the pursuit and crash.
An independent review team will look at the investigation once NSW Police inquiries have concluded.
NSW Police have internal guidelines for high-speed pursuits which are not publicly available.
After reviewing its safe driving policy in the wake of pursuit-related deaths in 2016, NSW police were criticised for not releasing the updated guidelines.
In September last year, a man died after his car crashed while being pursued by police near Gunnedah in north-west NSW, with a coroner report into the crash not yet available.
In April last year, a coroner delivered a finding into the death of a 17-month-old girl in a separate crash, who died after a police pursuit in Sydney's west.
A man being pursued by officers crashed through a fence into the backyard of the girl's Constitution Hill home where she and her three siblings were playing.
She was taken to Westmead Hospital and died an hour later.