Police remain mystified about the whereabouts of Frenchman Pierre-Antoine Paludet who has been missing in Hawke's Bay for four days.
There had been no reported sightings of the 32-year-old since he was seen beside his station wagon in a carpark near the river mouth at Haumoana about 6.30pm on Friday.
Detective Senior Sergeant Martin James, of Hawke's Bay CIB, said police are concerned for Paludet's safety and had formed a small team of police to investigate the disappearance.
A sea search was carried out on Sunday using drift pattern information, and another search for anything that could be linked with the disappearance was carried out yesterday in the Haumoana Domain and surrounding area, but nothing of interest had been found, James said.
Particularly concerning was that what seemed to be all of Paludet's belongings were with his vehicle which had been used for sleeping in as he travelled the country.
Police believed Paludet had been in the Christchurch area and travelled north recently, arriving at Haumoana last Wednesday and sleeping in the vehicle by the beach.
Police were yesterday still working with authorities in France to learn more about Paludet from his family, but they hadn't been kept up-to-date with his movements in New Zealand, which he appeared to like.
He appeared to have been in New Zealand two months on a work permit and had also visited New Zealand early last year.
Alexandre Paludet told Radio New Zealand he'd last heard from his brother on January 2, when it was to wish him a Happy New Year.
Pierre-Antoine Paludet was from Vallet, in the Nantes region about 370km southwest of Paris, and had studied at the University of La Rochelle to the south.
He had specialised in research into composite materials and had worked in construction and aviation engineering. At one stage he was employed by Airbus.
He was known as a traveller and adventurer, having sailed the Atlantic with friends in a small boat, but his brother said he doubted he would have ventured very far from shore had he entered the water at Haumoana.
James said police wanted to speak with anyone who may have associated with Paludet because it was important to try to establish more clearly his movements and plans in New Zealand, where he was expecting to stay another two to three months.
He was distinguishable by his broad French accent.
Mr James appealed to anyone with any information about Paludet to contact police, confidentially through Crimestoppers if necessary.