Kevin Belling, 62, was last seen at his Motu Rimu farm on Friday, January 9 and was reported missing on January 18.
Police have said they have "serious concerns" for his welfare.
In an update today, Detective Sergeant John Kean said search teams had conducted extensive searches, including at Mr Belling's Caeser Rd property in Kapuka.
"Southland Police are now proceeding to examine effluent ponds and other waterways on the Motu Rimu farm owned by Kevin," Det Sgt Kean said.
"Unfortunately, Kevin has not been found, and police continue to appeal for any information that could help us find him."
He asked people to be vigilant and to check their rural properties for any signs of Mr Belling.
Anyone with information was asked to contact police online at 105 or call 105, citing reference number 260118/6964.
Information can also be provided anonymously through Crime Stoppers on 0800 555 111.
- Allied Media
