Warning: This story discusses suicide and depression. 

As a group of sprightly morning walkers set off for a Boxing Day stroll along Canterbury’s Amberley Beach, they came across something odd. 

Strewn on the sand was nearly $10,000, which they collected and later handed to police. Further down the coast at Leithfield Beach more notes were blowing around. 

At a nearby carpark was a Subaru registered to Napier man Lewis Robertson, 37. His shoes were found near the high tide mark and further down the coast other walkers found a black bag that was believed to have been his. 

Eleven days later, on January 6, 2022, Roberton’s skeletal remains washed up on Leithfield Beach. More remains were found at Amberley Beach the next day. More of his remains appeared on the shoreline over the following week. 

The father-of-two had days earlier stolen $50,000 in a robbery of The Warehouse in Richmond, was acting erratically and believed he was being followed by police and drones.  

Today, Coroner Alexandra Cunninghame released her findings into Robertson’s death, concluding Robertson entered the water at Amberley Beach on Boxing Day in 2021.  

The cause of death will remain a mystery, with the coroner saying it was impossible to determine whether he died by suicide or an accident.  

According to the findings, Robertson split his time between Levin and Hawke’s Bay. He had struggled with methamphetamine use in the years prior and his father suspected he had depression.  

In 2016 he met a German national, Rebecca Merle. They married and had a child in 2016, but she was deported just days after giving birth.  

Robertson, unable to afford to follow her to Germany, turned to burglary to raise the funds. It landed him in prison for 18 months after stealing firearms and jewellery, according to an NZME report from the time. 

He lived with a friend once released from prison. He told this friend that someone was following him and he was “worried about white trucks”. 

In December 2021, Robertson travelled to the Kapiti Coast and later to Tauranga. He eventually made his way to Nelson, staying with his cousin and his partner, Jennifer Valk. 

He spent his time visiting beaches and meeting women, Valk said. His cousin recalled he was “going on about being chased and shooting at the pigs”. 

Robertson stole $50,000 from The Warehouse in Richmond early on Boxing Day 2021, after he was given the safe code by an employee. Photo / NZME 

One night the trio talked about burgling The Warehouse. Robertson committed the burglary in the early hours of Christmas Eve, assisted by Valk through her role as a security guard at the store. She gave Robertson the code for the safe, according to a court report from Stuff. 

Later the same day, Robertson bought a car advertised on Facebook using a false name. He drove to Kaikoura, dropping $800 on clothes, and later checked into a Christchurch motel. 

He visited a sex worker that afternoon, telling her he had been awake for a few days and was attempting to source methamphetamine. He found some, returning to the woman’s home the next day - Christmas Day. 

The pair went to the beach where Robertson swam. The woman said he appeared to be a strong swimmer. 

After the woman rejected his advances for a relationship, Lewis spoke to the mother of his child in Germany, who later said he was “fried on drugs”. 

He went to a petrol station at 8pm on Christmas night. Robertson’s final conversations were with the sex worker, who demanded money she was owed, and with Merle. 

“Becci they found me,” was Robertson’s last text to the mother of his child. 

Just after midnight on Boxing Day, CCTV captured Robertson driving south through Amberley. 

Cause of death unclear 

Robertson’s skeletal remains were identified soon after they were discovered. 

Forensic pathologist Dr David Taylor said there was no evidence of any trauma to the ribs, vertebrae or skull, but it was not possible to establish a cause of death. 

Taylor said it was “quite normal” for bodies that enter the water off the east coast of the South Island to be stripped to bones quickly, because of sea and sand lice and other small creatures. 

Police later investigated a rumour that Robertson was in trouble with gang members, but there was no evidence to confirm it. Police concluded no suspicious circumstances led to the death. 

Coroner Cunninghame said Robertson was far away from his younger child, while the rest of his family, including his older child, were in the North Island. 

He had been behaving in a paranoid manner, faced the prospect of going back to prison, and had been using methamphetamine. 

“All of these factors may have influenced his state of mind so that he formed a suicidal intention. Furthermore, he had mentioned suicide to friends and family in recent weeks,” Cunninghame wrote. 

But Merle said if Robertson had wanted to die by suicide he would have left notes. He would sometimes discuss suicide, but she believed he would never follow through. 

The other possibility was that Robertson decided to go for a night swim. 

“He may have encountered a rip or a large wave, or may have overestimated his swimming ability. Merle believed that Lewis was under the influence of drugs when she spoke to him at 10pm, and intoxication would have increased the risk.” 

Cunninghame considered a drug overdoes to be the least likely cause of Robertson’s death. 

She concluded he died on December 26 at Amberley Beach, either by suicide or an accident. She extended condolences to Robertson’s family. 

SUICIDE AND DEPRESSION 

Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• What's Up: 0800 942 8787 (11am to11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Helpline: 1737
If it is an emergency and you feel like you or someone else is at risk, call 111.

Ethan Griffiths covers crime and justice stories nationwide for Open Justice. He joined NZME in 2020, previously working as a regional reporter in Whanganui and South Taranaki.