Nelson Bays Police are appealing for sightings of 41-year-old British tourist Andrew Ian Wyatt, overdue on the Te Araroa Trail between Nelson Lakes and Boyle River.
Police are today tracing Mr Wyatt's bank and telephone records to try to eliminate the possibility he has left the area and is unaware of the concerns for his welfare.
A helicopter crew spent three hours yesterday visiting all of the huts in the area, but found no sign of Mr Wyatt, said Search and Rescue Coordinator Senior Constable Gerry Tonkin.
He said police were hopeful Mr Wyatt had changed his intentions and left the area.
"If he is still in that area then we have serious concerns for his welfare, given that he was last seen almost 10 days ago."
Mr Wyatt was last seen by a tramper at Blue Lake in Nelson Lakes National Park on or about December 14.
He was intending to tramp to the Boyle Village in Lewis Pass, where he was due to pick up a food package on December 16, but he never arrived.
His intention was to then carry onto Arthurs Pass where he had another food parcel to collect, police said.
Search coordinators say he may have now left the area where he was thought to be intending to tramp.
Police have been in contact with his parents in Cornwall, England, who said they had not heard from him since December 12.
Senior Constable Tonkin said police were very keen to speak to anyone who was tramping in the Blue Lake, Sabine Valley, D'Urville Valley area of Nelson Lakes National Park between December 13 and 19.
Mr Wyatt is 6ft 1in tall, with ginger hair and was carrying light equipment.
Contact Nelson Police on 03 546 3840. The Police event number is P015791441.
