A search has been stepped up in the Mt Field area for a missing 49-year-old tourist from New South Wales who is overdue to return to his home State.

Police Search and Rescue personnel plus volunteers, SES volunteers, a search dog, and the Westpac Police Rescue Helicopter are involved in the search for Paul Stephen Wilson.

Police have concerns for the welfare of Mr Wilson, whose movements have not been confirmed since the morning of Monday March 26 when he hired a vehicle in Hobart.

He was reported missing to Tasmania Police on Thursday afternoon, when enquiries were conducted, and a search was instigated on Friday afternoon.

His rental car was located yesterday afternoon at the start of the Mount Field East walking track on Lake Dobson Road. It is not known how long the car was in that location.

He is described as being of slim athletic build (approx. 65kg), 168 cm tall, mousey brown hair, blue eyes, Australian nationality, large operation scar on head and small scars above both eyes. He is believed to be wearing a sky blue outdoor fleece jumper, grey or black trousers and runners.

Police are concerned for his welfare due to his current medical condition. Police request anyone who has information as to his whereabouts to contact them on 131 444 or Crime Stoppers on 1800 333 000.

The search base and forward command post has been erected at the end of Lake Dobson Road adjacent to Lake Dobson. Inspector Stuart Scott and Sergeant Paul Steane are currently co-ordinating the search response. Insp Scott is available at the scene for interviews; phone interviews are difficult due to challenging communications in the area.