The father of the Kahui twins has told an inquest he blames his former partner for harming their twin sons after learning of affairs he believed she had with other family members.
Three-month-old boys Chris and Cru Kahui died after being admitted to a children's hospital in Auckland in June 2006.
Their father, Chris Kahui, was acquitted of their murder following a High Court trial in 2008.
It is the first time he has publicly spoken about the events leading up to the boys' deaths after choosing not to give evidence at the trial.
Mr Kahui originally told police he thought his former partner and mother of the twins, Macsyna King, could have injured the babies.
However, in his brief of evidence to the inquest he said he never saw her doing anything, but thought she must have.
Coroner Garry Evans told the inquest that the sexual relationships with two other family members are based on allegation.
However, he partially lifted a suppression order on Friday, stating the public is entitled to know the reason as to why Mr Kahui now feels Ms King must have harmed the twins.
All other details relating to the family members have been suppressed.
In his brief of evidence, Chris Kahui told the inquest that he left Ms King to do everything with the twins, however when cross-examined by police lawyer Simon Mount, Mr Kahui conceded this was not the case.
During cross-examination by Mr Mount, Mr Kahui told the inquest he had been careless and had read over his brief only once.
However, Mr Kahui's lawyer Christopher Wilkinson-Smith said the brief must be taken in conjunction with all the other evidence before the inquest from his client.
Mr Kahui will continue giving evidence on Monday.