UPDATED 2:43pm: A helicopter searching for two missing Canadian tourists has spotted one of the seats belonging to the campervan they were renting.
It's feared Connor Hayes, 25, and Joanna Lam, 24, have been swept off State Highway Six on the West Coast of the South Island by a massive slip.
The couple's vehicle was smashed to pieces after it went down a remote West Coast gorge in the South Island, in the midst of last week's massive storm.
16 police and volunteers are scouring the Haast River, with the help of a helicopter, two jet boats and ground teams.
Connor Hayes, 25, and Joanna Lam, 24, have been missing for a week - they were last seen on September 10 in Fox Glacier.
Last night a fuel tank from the vehicle washed up on the beach near the Haast River mouth - which is about 50km from where the couple's vehicle left the road.
Yesterday, police found the van's rear wheels and chassis in a region of Haast Pass, at Haast Gates, which has been battered by heavy rain and landslides.
The body of the vehicle and the engine have yet to be found.
Constable Robin Manera of Haast Police says it's possible the pair may have been swept off the road by the massive slip, which came down about the same time they were driving through.
"The vehicle's not that far from the slip, several hundred metres upstream. There'll be debris between where the vehicle is and the coast."
The road has been blocked since last Wednesday, after a massive slip came down.
A police spokeswoman said the helicopter searchers spotted one of the seats "about halfway" down the river towards the rivermouth this morning.
A media conference will be hosted by West Coast Area Commander Inspector John Canning at the Greymouth police station at 3.30pm today.
Campervan ignored road closure
A Haast resident travelling the Haast Pass highway on Tuesday said they saw an unknown campervan ignore the road closure warnings and drive up the valley.
The resident turned around after seeing the signs.
New life in NZ
The missing pair had been dating for two years and were planning a new life in New Zealand.
A special website set up by Jeffrey Lam says Joanna and Connor are loved by many back home in Canada, and friends and family are desperate to have them found.
It says work of the Search and Rescue team in New Zealand is greatly appreciated.
Miss Lam was due to start working at the radiology department at Nelson District Health Board on Monday.
A spokeswoman said the board's chief executive Chris Fleming was "very concerned" about her disappearance.
Mr Hayes' older brother Lliam, 26, told the New Zealand Herald last night the family were holding out hope the couple were alive.
He said their spirits were "not the greatest, but still optimistic" and they had no immediate plans to come to New Zealand.
"Connor brought Joanna to New Zealand to get her settled for her new job. [They have] both done a lot of travelling before," he said.
Regular updates from his brother, who was due to start training for Canada's police force on his return, stopped last week.
"They were having a great time. He had been sending email updates to my family - the last one on September 8. He was going on a glacier tour on the 10th and that's his last-known whereabouts."
The couple had been dating for almost two years, a friend of Lam, Tamara Sagadore told Canadian media.
She told CBC News the pair had been travelling in South America before coming to New Zealand to work in Nelson on a six-month contract.
Ms Sagadore described the pair as a "perfect fit".
"I think it's just really difficult because everything's so unknown, especially because it's from such a distance. I spoke with her right before she left and she was just so excited and optimistic, and now this happening. It's almost unfathomable," she said.
Lam's aunt, Jennifer Lam, told CBC News: "I'm being very optimistic and wishing for the best. All my hope is that they're okay."
A Twitter feed, #findjoandconnor is busy with messages of support and hope from friends.
"Hope they will be found...safe & sound," said one message.
Matt Thibault, a long-time friend of Lam who went to school with her in her hometown of Kingston, has been keeping in touch with New Zealand police, the Toronto Sun reports.
"It's been tough the last 24 hours keeping the hope up that everything is going to be okay," he said.
"Everyone has been trying to piece together what happened."
Police liaison are in continuous dialogue with the families with the Canadian Embassy, a spokeswoman said.
NZTA assisting police
The New Zealand Transport Agency will assist police in their search for the missing Canadian tourists.
Contracting crews from NZTA have been working on State Highway Six, near the Gates of Haast Bridge since last Wednesday, after a 30 metre large slip came down onto the road.
The Agency's West Coast highway operations Mmnager Pete Connors says Police are leading the investigation and the Transport Agency will help them in whatever way they can.
Photo: Joanna Lam and Connor Hayes (Supplied)