Despite being missing since March, locals in the remote Caitlins area insist John Beckenridge and his 11-year-old stepson Mike Zhao-Beckenridge are still alive.
People who served Mr Beckenridge in the days before he vanished say it's likely he's fled the deep south, where the pair was last seen, the New Zealand Herald reports.
Kevin Millard, who works at Tokanui General Store, served the missing pair two days before the police issued a public missing persons plea for help.
Mr Millard told the New Zealand Herald it was unlikely the duo was still in New Zealand.
"He's not hiding out round here, there's too many hunters and people that would've come over them."
A missing persons alert was issued the day Mike disappeared and police issued border alerts within the next 24 hours, but a top criminologist and aviation expert say it would be possible to escape the country without being detected.
Mr Beckenridge picked up Mike from James Hargest College's junior school in Invercargill on March 13 and the pair have been missing since.
On March 20, Mr Beckenridge sent goodbye texts to his ex-wife, lawyer and friends and within the next 24 hours his car was found driven off the side of an 88m cliff near Curio Bay.
The vehicle wreck took six weeks to be recovered and police found no signs of human remains in the car.
A police spokesman said potential sightings were still being reported across New Zealand but officers have ruled them all out, the Herald reports.