This Sunday marks a year since the disappearance of 12-year-old Mike Zhao-Beckenridge and his step-father John Beckenridge.
Police say they're aware there are unanswered questions and the case remains open as a missing person's case.
Detective Sergeant Stu Harvey says he shares the frustrations of the family as to what happened to the pair.
There have been reports of the pair both in New Zealand and overseas, but Det Sgnt Harvey says these have been investigated and are unconfirmed.
The last confirmed sighting was in March 2015.
They've worked with Mike's mother since the disappearance and say their ultimate goal is to bring closure to the family.
Indications are the pair never left the Catlins area, but police won't hand over the case to the coroner until all inquiries are exhausted, including overseas inquiries.
John Beckenridge (File)
Mike was reported missing by his mother, Fiona Lu, on March 13 after not returning from his lunch break to James Hargest Junior Campus in Invercargill.
What ensued was week of questions with no answers, particularly after Mr Beckenridge's car was found in the sea at the bottom of a cliff in Curio Bay with no human traces.
Tyre tracks leading off the cliff indicated someone was in the car and it left the ground as it went over the cliff.
Several text messages off the 64-year-old's phone were sent the day before the car was found to his estranged wife and solicitor.
At the time, there were suggestions it was a murder-suicide, however others are of the firm belief the pair are still alive.
Police evidence points to the pair having never left the Catlins area.
The Swedish-born helicopter pilot has four known aliases: John Locke, John Robert Lundh, Knut Goran Roland Lundh and John Bradford.
After the disappearance there was a reported sighting of the pair in a remote area of the Catlins by Southland farmers. This remains the only confirmed sighting since.
A helicopter recovering the car in Curio Bay (File)
TIMELINE:
March 13
Mike Zhao-Beckenridge, 11 at the time, is taken from school by his step-farther John Beckenridge.
March 16
Reported sighting of Mike and Mr Beckenridge in the Catlins by Southland farmers.
March 18
Police appeal to the public for help to find the pair, thought to be travelling in a dark-blue Volkswagen Touareg.
March 22
Car parts and a backpack in the Tokanui and Haldane areas are found washed up on a beach in Curio Bay.
March 23
Police divers attempt to search the Blue Cod Bay area, but conditions are rough.
March 24
Police find vehicle wreckage in Blue Cod Bay.
March 25
The wreckage is confirmed as Mr Beckenridge's Volkswagen Touareg.
April 8
Evidence points to the pair being in the car when it flew off the 88-metre cliff, police say.
May 6
The car is recovered and taken to Bluff by boat
May 18
No human traces are found in the car
April 2015
An unconfirmed sighting of the pair is reported to police
READ MORE:
Search for missing boy Mike Zhao-Beckenridge suspended
Zhao-Beckenridge case will remain unclosed
Mike Zhao-Beckenridge search: mother holds onto hope
Submerged car belongs to John Beckenridge
Locals insist Beckenridge pair still alive
Mike Zhao-Beckenridge search: Helicopter lifts car
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