Police say they will consider offering immunity against prosecution to anyone who may be harbouring fugitive Tom Phillips and his children, if they give up information on them before June 25.
Ember, Maverick and Jayda Phillips have been missing since December 12, 2021, when they were taken by their father to an unknown location - but thought to be in western Waikato within Marokopa or the surrounding areas.
Police said there are concerns for the welfare of the children, who have been living in isolation for two-and-a-half years, with no connection to others and without formal education and health care.
And they are offering a reward of up to $80,000 for information that leads to the children's safe return.
A police team has also been deployed to Marokopa as part of a new phase in the missing persons investigation.
In a statement on Tuesday, Det Insp Andrew Saunders said it's believed Phillips and the children are being assisted and they're urging whoever is doing so to stop.
"We are committing to finding these children and we're willing to take the step of offering a reward if it will prove the tipping point to help people put the children's welfare first."
The Police Commissioner will determine the amount of the reward and will apportion it if there is more than one claimant.
Immunity against prosecution will also be considered for anyone who has committed an offence in assisting Phillips, if they provide information or evidence which leads to the location and safe return of the children.
The offer will remain in force until June 25, police said.
Saunders reiterated Phillips is facing serious charges in relation to aggravated robbery, aggravated wounding and unlawful possession of a firearm as a result of a criminal investigation separate to the missing persons case.
Anyone with information on their whereabouts is urged to contact 105, quoting the file number 211218/5611.
Saunders was expected to provide more information during a press conference at 2pm.
