Mike Zhao-Beckenridge, missing for nine days, was believed to be willingly with 64-year-old John Beckenridge in the remote Catlins area of Southland.
"Police staff along with Search and Rescue volunteers have carried out an extensive search in the Haldane and Tokanui areas in Southland," Detective Sergeant Mark McCloy said in a statement today.
Mr McCloy said police were now examining several objects thought relevant to the missing duo.
"Following the items being located, Police staff, search and rescue volunteers and a helicopter have conducted a further search [near] Curio Bay," he added.
"We really want to resolve this situation," Mr McCloy said earlier this week. "John can call me via 03 471 4800 at any stage and talk with me personally about his situation."
The duo were earlier thought to be travelling in a dark blue Volkswagen Touareg station wagon with the license plate DUY263.
