Man dies after falling from moving car near Hobart

A man died after falling from a moving car north of Hobart on Friday night.

Police say the car was travelling south from Launceston along the Midland Highway when the 21-year-old fell out on the Brighton Bypass.

Sergeant Rod Carrick said the man's 18-year-old girlfriend from Bellerive, who was driving, stopped the car and tried to revive him but he died at the scene.

"It would appear that something may have occurred in the motor vehicle at the time and that's what's presently under investigation," he said.

Sgt Carrick said the driver was not affected by alcohol but the dead man may have been.

It is understood the incident occurred on a 110kph stretch of the Brighton Bypass.

Crash investigators say they were still determining how fast the car was travelling at the time.

Both the driver and the 19-year-old female front-seat passenger from New Town are described as being traumatised.

Police want to hear from anyone who saw what happened.