Justice Raynor Asher discharged the man and told the 11 remaining jurors that he would decide on a way forward later this afternoon.
The case may continue regardless, a replacement juror may be added or a whole new jury of 12 might be selected tomorrow.
Mr Clancy today told the jury Reddy admitted the murders to undercover police officers - including how he strangled his partner with an electrical cord, smothered her daughter with a pillow, and buried their bodies.
"Mr Reddy said he went to that site at night and it took him hours, working alone, to dig a hole big enough to take both bodies, under the bridge beside a creek.
"He gave details."
The Crown says those details, including the placement of the bodies and what they were wearing, can be backed up by independent evidence.
Mr Clancy said the jury would also see and hear recorded conversations, in which Reddy tells undercover officers how he killed the victims, and hid their bodies in a muddy grave under the Takapuna overbridge.
"What you will see is a man unburdening himself of a terrible secret that he's carried with him for years.
"Pouring out details that only the person who murdered Pakeeza and Juwairiyah could have known."
The trial is set to last four weeks.
