Christchurch police are looking for Mark Childs, 53, who has been missing since October 6.
Childs is European, 172cm tall and of medium to solid build. He has a tattoo on his upper right arm.
A police spokeswoman said they had concerns for Childs' safety and he was not a danger to the public.
Police believe Childs could be in Christchurch or Picton. They ask anyone who has seen him or knows where he is to contact their local police station.