The father of Baby Leo is preparing to sue the Exclusive Brethren for "psychological abuse" according to documents.
Samuel Forrest was excommunicated from the Exclusive Brethren church in Wanganui and as a result lost contact with his four children. He says he has suffered "alienation of affection", according to Fairfax Media.
He reportedly told family members this month about plans to launch a lawsuit against the church he grew up in, for $1 million per child 'lost'.
Mr Forrest told Fairfax Media that although this issue is on hold, world-wide support for class action is increasing.
Mr Forrest appealed for donations to look after his Down Syndrome son solo in New Zealand after his Armenian wife disowned the baby.
However the couple have reconciled and now live in Auckland, and allegations over Mr Forrest's spending of the donated money have been raised by former trustee Trina MacLachlan.
Ms MacLachlan is concerned that funds from the Leo Forrest Trust will now go toward the legal battle.
Mr Forrest told Fairfax Media there was general discussion about this but no plans to do so just yet.
Mr Forrest wrote in a letter to family that he will claim damages for human rights denial and psychological abuse.