More details about the discovery of a tramper missing almost three weeks in Tasman bushland

66-year-old Graham Garnett didn't return from Kahurangi National Park on December 30, and searches were called off on Thursday.

But yesterday, contractors installing Department of Conservation pest control signs discovered him alive in the park's Venus Hut.

Heliventures NZ chief executive Nicki McMillan says it was a fantastic outcome, in a case of right place, right time for her staff.

Garnett's been reunited with family, at Nelson Hospital.