A man accused of a cold case murder told under-cover police officers he strangled a woman with an iron cord and smothered her daughter with a pillow.
Kamal Reddy has denied murdering Pakeeza Yusuf and her three-year-old daughter, Juwairiyah Kalim, 10 years ago and is on trial at the High Court in Auckland.
Ms Yusuf and her daughter, known as Jojo, went missing in late 2006 but their bodies were only discovered under a bridge on Auckland's North Shore eight years later.
Secret audio recordings of the six month-long police undercover operation have been played while the court was closed to the public.
Widespread suppression orders are in place but RNZ can report Mr Reddy was asked to disclose secrets to the officers.
He told them he'd strangled Ms Yusuf with an iron cord and then smothered her daughter with a pillow.
The court has also heard that Mr Reddy took an undercover police officer to the spot under a motorway overpass where the bodies of his ex-partner and her daughter were later found.
In his opening address, Mr Reddy's lawyer Jonathan Krebs told the jury his client falsely confessed to officers.