An inquiry into the disappearance of Tom Phillips and his children will analyse if New Zealand met its obligations under international law

The four year search for the group ended in a shootout last September, where Phillips severely injured a police officer, before being shot dead.

An inquiry into their disappearance will begin hearing evidence today - looking at whether agencies should have done more - or acted faster to protect the children.

Waikato University Senior Law Lecturer Anna-Marie Brennan says New Zealand has obligations to protect children under UN conventions.

She says children deprived of their family environment must be given special protection and assistance.