A fathers' lobby group says it is time to stop picking sides in custody battles and find what is best for the child.

His comments follow the indefinite jailing of a Hamilton mother, 35-year-old Kay Skelton, for refusing to reveal the whereabouts of her son Jayden Headley.

Coalition of Fathers spokesman, Jim Bagnall says if the courts took Australia's lead and made the presumption of shared custody, parents would not take such drastic measures.

Mr Bagnall says he is sure the child would be happy to know he could spend half the time with Dad, and half the time with Mum.

He says society needs to stop taking sides and start considering what is best for the child. He says children need both parents so there should be a good reason to distance a child from one parent.