“You do not deserve to be my mum. You certainly do not deserve my love.”

That was the message a mother received from her 11-year-old son before he and his stepfather disappeared in 2015, never to be seen again in one of New Zealand’s most baffling missing persons cases.

Swedish-born helicopter pilot John Beckenridge broke a court order and picked up his 11-year-old stepson, Mike Zhao-Beckenridge, from his Invercargill school on March 13, 2015.

A week later Beckenridge’s dark-blue 4WD Volkswagen Touareg went off a 90m cliff near Curio Bay.

It took police six weeks to recover the battered wreck from the treacherous waters and there was no sign of any bodies.

However, Mike’s mother Fiona Lu is convinced her son is still alive and her former partner staged the pair’s death after she moved her son away from Beckenridge’s Queenstown home to Invercargill with her new partner.

Mike Zhao-Beckenridge disappeared with his stepfather in March 2015. Photo / supplied

Now, Coroner Marcus Elliot will look into the case at the Christchurch District Court to consider whether it is likely the pair are dead.

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The hearing which began on Monday is expected to take two weeks and will hear evidence from witnesses including someone who believes she spotted the pair overseas four months after their disappearance.

Police have spent thousands of hours investigating the case but have had no success in finding out exactly what happened.

Mike would now be aged 18.

The court heard openings from Lisa Preston KC, assisting the Coroner, outlining the background of the case.

Beckenridge met Mike’s mother, Lu, who is from China, in 2006. Lu’s parents were raising Mike at the time.

John Beckenridge's car was found at the bottom of an 88m cliff near Curio Bay. Photo / Otago Daily Times

The pair later moved to New Zealand with Mike where they were based in Queenstown. Their relationship broke down in 2014 shortly after Lu moved to Invercargill.

In February 2015 the Queenstown Family Court made an order that Lu had care of Mike.

Mike was unhappy to be taken away from his stepfather and was secretively communicating with him by email, pleading for Beckenridge to come to take him away from his mother and her partner Peter Russell.

Mike told Beckenridge he was misbehaving so he could be sent back to live with his stepfather. He also called the police on one occasion, saying his mother had assaulted him in hopes he would get sent back to Queenstown.

On March 13, 2015, Beckenridge dropped off a box of documents and a letter for his Queenstown-based lawyer asking him to contact his friend in relation to his trust fund and estate.

The letter read: It will now be up to him how to do with what is left of my “belongings” ! Thanks for your assistance over the years . Very helpfull !”

Fiona Lu, the mother of Mike Zhao-Beckenridge, believes her son is still alive. Photo / supplied

That same day, Beckenridge took Mike from his school sometime between a pre-lunch roll call and the end of the day and drove them to the southern Catlins area.

Police were alerted and a search party was launched, with concerns raised about the risk of a murder-suicide.

Border alerts were put in place, including for Beckenridge’s aliases Knut Goran Roland Lundh (his birth name), John Robert Lundh and John Bradford.

On March 19 police located a campsite off Weir Road on the Haldane Estuary and the pair’s fingerprints were detected on some items.

The next day Beckenridge’s friends began receiving “concerning” texts from him, stating the “Gestapo” was after him and Mike and they would soon be getting on the “Midnight Express” for departure.

Heartbreaking messages to Lu from Mike expressed his frustration at her not listening to him, stating “you do not deserve to be my mum or to be called Fiona and you certainly do not deserve my love. From Mike.”

Beckenridge also sent a message to Lu, thanking her for being his wife while also accusing her of lying and deceiving.

John Beckenridge.

On March 22, items belonging to the Beckenridges such as clothes and car parts washed ashore in the Curio Bay area. Soon after Beckenridge’s vehicle was found at the bottom of the cliff in the water.

Tyre marks found at the top of the cliff were analysed by an expert, who will give evidence during the hearing.

A stake made from two pieces of wooden stick tied together with a rope was also placed 10m from the cliff edge, something police suggest was used to give a sightline to the cliff edge.

A senior constable who analysed the likely speed the vehicle was travelling before it went over the cliff indicated it was not possible for a person to safely exit the vehicle at a minimum speed of 45km.

The Police National Dive Squad were able to dive on the wreckage of the vehicle on March 29 but it wasn’t until May 6 that the vehicle was able to be recovered.

There had been extensive further damage to the vehicle from when it was first discovered, and no forensic evidence was detected.

Since then, police have spent thousands of hours investigating the case but have been unable to solve it.

The hearing before Coroner Elliot continues.