On Sunday, the teams began searches of that area.
"He's out there and we've got a list of areas that we now know he's not in," Fraser said.
"We are confident of finding him."
Nigel, who was under 24-hour care, was with a caregiver just after 3pm on Friday November 17 when he got out of the car on Otonga Rd.
He was last seen on Old Taupo Rd and after reviewing CCTV footage police believe he made his way south.
So far the team have searched more than 1000 private properties, walking as far as 28km each day.
On Sunday, the BayTrust Rescue Helicopter's inflatable rescue boat did a shoreline search of the Green Lake, with the blessing of iwi.
Meanwhile the team at Heli Resources in Murupara have given the search team the use of one of their helicopters for two hours on Monday.
"It's just a local business who want to help the family," Fraser said.
Fraser said it had been a very unusual search with the lack of sightings they had received and the lack of information coming in.
"We follow up on all the information we receive, so ring us and tell us what you know.
"I would love to be able to ring up the family and say we've got him."
Fraser said the family were continuing their own searches as well.
"They are working alongside us to maximise the resources."
Nigel's dad Chris Peterson said it had been a long week.
"Our feelings go up with any new information or the slightest hope, but every time, the end of the day comes and we have still not found him.
"It leaves us distraught."
He said the support the family received had been great.
"We still believe Nigel has been out of public view, lost or hiding in the area south of Rotorua.
"There is plenty of water to be found and he would survive without food, the weather has been kind too."
The family and friends have been staying together at the thermal park and Peterson said today at noon they held a karakia to pray for Nigel and to help them through this.
Nigel Peterson's description
• 33
• Slim, medium height
• Wearing a green T-shirt, light brown pants, brown sneakers and possibly a denim jacket
• Often wrings his hands and could be talking to himself
• Walks with an unusual gait and leans to the side as he moves
Any information can be given to Rotorua police on (07) 348 0099 or the anonymous Crimestoppers line on (0800 555 111)