The parents of missing Australian tennis coach Paul Arber say he was behaving oddly before his disappearance in Hamilton.
Arber, 38, was last seen on Saturday night in Hamilton, after going out for dinner with a group of friends.
His parents, Richelle and Sam Arber, flew in from Melbourne on Sunday.
Today they issued a plea for help from anyone in Hamilton who might help police find him. They also spoke of their worry for their "loving and caring" son.
Arber had been very passionate about being close to nature, animals and people in the weeks just before he came out to New Zealand, they said.
He was also encouraging his parents to follow his "newfound love for these things".
That struck his father as odd.
"I was a bit concerned because he seemed a bit too passionate about it," he said.
"It did disturb me slightly but I thought: 'he's going to New Zealand, I'll talk to him when he's back'."
Richelle Arber said their son had spoken to them about leading positive lives.
"Paul was positive and he wanted us to be positive so through all of this we are remaining positive."
In a Facebook post they said they were "distraught with worry" but "we feel that he is still alive but in an irrational, psychotic state".
Police today resumed their search for Arber, saying finding his clothes, abandoned when he went for a swim in the Waikato River, would be crucial to the investigation.
"When Paul was seen about 10pm on Saturday he was wearing quite distinctive blue, orange and white Adidas sports shoes and a grey Wilson's tracksuit," Detective Inspector Karl Thornton said.
"But when seen in the Waikato River he was described as only being clad in a pair of black shorts."
A search boat was launched on the river at 8am today, and land-based teams are scouring the river banks, parks, walkways and buildings in Hamilton.
Police have requested people to search their properties and neighbourhood for any items of clothing or property that may seem out of place.
Longtime friend Nathan Hude has also shed light on sightings after they lost sight of Arber on Saturday night.
Hude wrote on the Find Paul Arber Facebook group page that Arber had approached a family in their driveway after 9pm and spoke to them, "offering fruit, about spirituality".
"Later at around 10pm he spoke to some more people further down [the] street and turning right, near Galloway
Park with similar story. [He] was seen carrying what were thought to be grocery bags, containing at least the fruit he was offering people."
Hude said that suggested Arber was in a state of mind of wanting to help people.
RIVER A CLUE
Police have also moved the mobile police station that was in Grey St to Victoria St by the Waikato Museum, today.
The area is nearer the last confirmed sighting of Arber, by the western river bank near the Victoria Bridge.
Police refocused their search for the Melbourne man yesterday after two people reported seeing someone in the river under the Victoria St Bridge at 4am on Sunday.
They went to the river's edge and talked the man out, Thornton said.
The man told them his name was Paul and he was in Hamilton for a tennis tournament. He was dressed in dark shorts yet he had been seen earlier that night wearing a grey tracksuit.
Thornton said the man walked up the stairs and partway across the bridge with the pair.
"They've been trying to get him back to where he was staying and then he has, for some reason unbeknown to them, turned around and walked back down to the river area."
Police scoured the river banks on foot in response and searched the waterway from the police boat. The Eagle chopper also searched from above.
Arber was in Hamilton coaching eight young tennis players who competed in the Waikato Christmas Junior Tournament at the tennis centre in Dey St. He was part of a wider group of about 50 Australian coaches and players.
- © Fairfax NZ News