It has been almost two years since children Jadya, Maverick and Ember disappeared from Marokopa with their fugitive dad Tom Phillips - and police are increasingly concerned they are being dragged into crime.

Phillips reappeared briefly last week, caught on CCTV allegedly trying to break into the Piopio Superette - and he had a helper with him.

That person was heavily disguised, but police believe it was one of his children, who are now aged between seven and 10 years old.

One of the last times Phillips was seen, he was allegedly armed and robbing a bank in Te Kuiti.

Police say he had a petite person helping him then, although they could not say if it was one of his children.

At the time, a witness told Checkpoint it was a girl and she was armed too.

Clinical psychologist Dougal Sutherland told Checkpoint there are significant questions about the children's welfare.

"The first concern is their level of isolation, being away from extended family, from their mum and out of circulation with the rest of the world.

"The other concern is what is the state of mind in the family environment they are living in, that would make it OK for them to engage in this sort of behaviour, to break in to shops. 

"It speaks to how long they have been away from the rest of society. The problem is none of us have any information about the kind of environment they're living in... One (theory) is that (Tom Phillips) is being very authoritative and directing, instructing, forcing the kids into doing this. 

"More likely is a situation where dad and the other people who've been around have developed a world (view) that this sort of behaviour is necessary, is OK or is allowable, just by the fact they've been away from society for so long... Nobody really knows for sure, of course.

"They probably know at some level that doing this is wrong so there has to be some way of reconciling that, for them to engage in this behaviour, if it's not just because dad is forcing them to do it."

Sutherland told Checkpoint it will be harder for the children to reintegrate when they are finally returned.

"The reintegration process would need to be really slow, careful and step by step. Imagine if any one of us had been locked away from broader society for two years and then stepping back into the hustle and bustle of what's happening in the world. It would be a big shock for any of us, let alone for a child.

"It would be important to learn and understand the world view that their father had woven for them, he said, before "very gently testing that, challenging that and introducing them to other ways of thinking. But that will be a slow process because I imagine they feel quite strongly connected to dad, rightly or wrongly." 

Just because they have been out of school doesn't necessarily mean they have had no education, Sutherland says.

"You could imagine a bush classroom, (where) they might be being taught to read, write... But they're certainly well outside the usual education system for most children and as it goes on that will have more and more of an impact."

In a statement, Oranga Tamariki says it has been supporting and working alongside police, and staff had been across the issue since Phillips and his children first went missing.

A spokesperson says its priority is the children and ensuring they are safe and well.

It's in the best interest of the children for anyone with information to contact police or Oranga Tamariki urgently, the spokesperson says.

-RNZ/Checkpoint.