Paul Kevin Canning, known as ''Cannon'', was reported missing to police at 2.30pm on Monday, and had not been seen since 10pm on Sunday.
Senior Sergeant Jason McCoy said search and rescue teams searched the South Hill area for Mr Canning on Monday, until darkness halted the search about 8.30pm.
However, search teams restarted at 8am yesterday and the man was found in an empty building in Oamaru about 3.30pm and was now safe and well.
Snr Sgt McCoy said police had been ''extremely concerned'' about Mr Canning's well-being, due to his reported state of mind at the time he went missing, and thanked the public for their assistance in locating the man.