It's been 48 hours since Orewa man Mike McClennan went missing, and his family and the police say their search for him is reaching a critical point.
The 75-year-old was last seen on Wednesday evening, walking north on the Hibiscus Coast Highway, near Hatfields Beach.
A well-known figure in rugby league, he's the father of Brian McClennan, the former Kiwis and Warriors coach.
"We're really worried our family, because he's been gone since Wednesday night, he's got severe dementia," Brian McClennan said.
"Because he's left and got out and taken off, he's not taken any meds, his health will be declining rapidly - this is getting to a really serious state."
Brian McClennan said it was possible someone had given his father a lift - and if that was the case, he urged that person to get in touch with the police.
Search and rescue teams and a helicopter have spent the last two days combing the area for any sign of the 75-year-old.
Family and friends had joined the search, Brian McClennan said.
"We've been out searching all the areas too, around the beaches, rocks, up the roads, down the sides of the roads," he said.
"All the family's been out every day and night, first thing in the morning."
Brian McClennan said his father's health had been declining over the last few years.
"He got admitted into hospital three weeks ago and from that hospital he got sent into a home because of his condition.
"Unfortunately because of his dementia he thinks the hospital and the home were prison and that's why he's tried to escape."
Senior Sergeant Brett Henshaw said they want to hear from anyone who may have seen Mike McClennan, and they're asking drivers to go back through their dashcam footage if they were in the area where he was last seen.
"This is a race against the clock, we're over 40 hours now, he's a 75-year-old man, he's on medication, this is getting critical for him."
Locals are being asked to check their backyards, sheds and holidays homes for anything that may help with the search.
Anyone who has information or sees Mike McClennan should call 111.