"We're hoping that a fresh look at the case, and an appeal for information, will also turn up some new leads.''
Police had an open mind as to his fate.
"Given the length of time that has elapsed with no sightings, however, we believe Mr Hendry is dead, and we clearly can't rule out foul play,'' Mr Fitzgerald said.
Mr Hendry was last seen at his home at 45 Tabart Street where he lived with his parents and brother.
About 4.30 pm that day he was believed to have left the house in his orange Datsun 120Y, registration HS359, to go to the St Martins post office to withdraw money. Neither Mr Hendry nor his vehicle has been seen since.
Mr Hendry's distinctive hand-painted car had no front passenger seat, and would have attracted attention because of its poor condition.
"During the police enquiries that followed it was established that he didn't make it to the post office, which was about two kilometres from his home,'' Mr Fitzgerald said.
At the time of his disappearance, Mr Hendry was suffering from a mental health condition that required him to take medication, but his medication was left behind, as were all of his possessions and passport.
He was also known to have been planning holidays at the time he disappeared and was also known to holiday on the West Coast and in the Kaikoura area.
Mr Hendry is survived by a brother and three sisters.
"Since Terence's disappearance his mother and father have passed away without knowing what happened to him. It would be good to be able to achieve some closure in this case,'' Mr Fitzgerald said.
Anyone with information is asked to contact Detective Sergeant Al Lester at Christchurch police on (03) 3637400. Alternatively, to provide information anonymously contact Crimestoppers on 0800 555 111.