Key Points:

DNA tests have confirmed that Chris Kahui is the biological father of murdered twins Chris and Cru, following questions over their paternity.

Not even the twins' mother Macsyna King, or Kahui, knew for certain that he was the true father until the paternity tests came back positive, according to a source close to the investigation.

Crown prosecutor Simon Mount, Kahui's lawyer Lorraine Smith and Counties Manukau police all declined to comment as the case is before the courts. Kahui is charged with murdering his twin infant sons in June last year.

The 22-year-old is due to appear in court for a second pre-depositions hearing in two weeks' time, when the Crown and defence lawyers will provide lists of witnesses they wish to call and cross examine at the hearing in June.

The defence has been delayed as an Australian expert has been slow to analyse the medical evidence which is crucial to the police case against Kahui, expected to reveal the approximate time the fatal injuries were inflicted on the babies.

Last October, the Herald on Sunday first reported that police had suspicions over whether murder accused Chris Kahui was the real father.

Family members confirmed that police had questioned them over the twins' paternity.

"We believe he is the father and that he did nothing wrong," said Kahui's sister Mona-Louise only days after he was arrested and charged.

She was one of four family members living in the Mangere home at the time the twins died.