The 30-year-old Waverley man was travelling in the back of a car when it left the highway and slammed into three gumtrees on the Launceston side of the Alanvale Connector turnoff a little after 1am.

He died in the Launceston General Hospital Monday night as a result of his injuries.

A 29-year-old Ravenswood man was also injured in the crash. He remains in a satisfactory condition in hospital. Northern Traffic Inspector Darren Hopkins said police were interested in talking to people who may have seen the silver Nissan wagon on the East Tamar Highway or at the BP petrol station in Newnham before the crash.

''We are seeking public assistance to try and identify the two people who left their friends for dead,'' Inspector Hopkins said. He said police were also interested in talking to anyone who may have seen two men, believed to be the driver and the front seat passenger at the time of the crash, running away through the Australian Maritime College grounds.

Anyone with information is asked to call Crime Stoppers on 1800 333 000 or police on 131 444