Human intelligence is the only way police can find fugitive Tom Phillips and his three children, an expert says.
Police continued to sift through more than 70 new leads since offering an $80,000 reward.
Phillips went awol from Marokopa with his children Ember, Maverick and Jayda two and a half years ago.
He was wanted in connection to a bank robbery, attempting to break into a grocery store and even stocked up at the Hamilton Bunnings; all the time managing to evade the police.
Australian David Craig was a former Detective Superintendent and federal agent, and also the chief hunter on a TV programme where experts chase down and capture fugitive contestants.
He told Checkpoint there was "not a chance" Phillips would still be at large if he was leading the hunt, saying two and a half years was "too long".
Former Australian federal agent speaks on hunt for Tom Philips
An interesting fact was Phillips had gone on the run in the bush before and then come back, said Craig.
"While he was gone for that 17 days ... in that dense bushland in a tent with his children, what did he learn that wasn't going to help him continue to go longer than 17 days, because he's come back for a reason.
"What he's doing now, [he'd] learnt from that first experience."
Craig said he would be looking at purchases and phone calls Phillips made in the three month period before he disappeared a second time.
"Were there any thefts of local motor vehicles or things that could be used to evade authorities in that three month time period."
'Neglectful and abusive'
Craig said the only way police were going to find Phillips was through human intelligence.
He believed the $80,000 reward for information leading to Phillips capture was a good step, but he said that was not enough for someone to give up their best friend or close family member.
"What I think needs to be reinforced in the public's ear is that what is occurring to these children is actually neglectful and abusive under the Child Services Act in New Zealand.
"It's one thing to protect Tom Phillips ... but it's another thing if you're protecting a person that is abusing and neglecting children, so that is a criminal offence in New Zealand."
Craig said he would be keeping a close eye on family and friends of Phillips.
"If I thought that someone was turning a blind eye to child abuse, child neglect, and a wanted fugitive, I would be all over that person like black on a crow.
"Any person that's doing that, they need to be covered electronically, and with human interviews ... and is quite justified in doing so because you're talking about the welfare of three minors in this case.
While Phillips did not have a digital footprint, Craig said some technology could still be useful to track him down, such as military and commercial satellites.
"You're talking about four people moving through the bush for two years or so, they would have some regular paths that they follow. These should be shown in timeless form over the two year period.
"It would also show thermal imaging at particular hours of the night, which may show people lying in a particular area."