'We just want to find him': Search for missing former Kiwis league stalwart Mike McClennan approaches night 6

The family of missing Kiwis rugby league stalwart Michael McClennan are "holding onto hope" as the search enters night six.

The 75-year-old went missing from the Milton Court Rest Home on Milton Rd, Orewa on Wednesday, sparking a massive search effort.

Brian "Bluey" McClennan, himself a former Warriors and Kiwis coach, said his father's dementia had intensified over the past several years and the family was getting increasingly worried for his safety.

"We just want to find him. We are holding out hope that he is alive, but each day the chances are getting slimmer and slimmer."

He was last spotted about 5pm last Wednesday walking north on the Hibiscus Coast Highway, wearing a red and black cardigan and blue jeans.

Former New Zealand Warriors coach Brian McClennan said there had been fantastic community support in the search for his missing father Mike. Photo / File

Brian McClennan said they initially thought somebody might have picked his father up unaware he had gone missing, but given how long it had been that was looking less likely.

"We think by this point somebody would have said something if they had seen him."

His father's dementia had developed over the past four to five years, and he was now at a stage where he needed to be in care, Brian said.

"He is a good, kind man, but very confused. His favourite place to go back to is the city, Maidstone St in Grey Lynn, where he grew up - in his mind he is still there, and Fowlds Park where he coached a lot of rugby league."

Police have set up an information truck at Waiwera while they look for missing former rugby league coach Mike McClennan. Photo / File

The community support in the search effort had been "fabulous", he said.

"We are really thankful for all of the support we are getting, from friends, police and the wider community, it has been fabulous."

Police have set up a mobile truck at Waiwera and were asking for information from the public.

Senior Sergeant Brett Henshaw said they were still in a search and rescue phase and continued to appeal to anyone who had information to contact police.

"Police and Mike's family have been blown away by the amount of support they have received and we continue to ask people in the wider Orewa area who have not already checked their sheds and properties to please do so."

Anyone with information was asked to contact Henshaw on the police 105 number.