A juror suddenly became ill at David Bain's retrial, calling a halt to proceedings on Thursday.
The trial may resume on Friday in the High Court at Christchurch, if the juror is well enough.
David Bain is on trial for the murder of his parents Robin and Margaret, sisters Laniet and Arawa and brother Stephen, at the family home in Dunedin on 20 June 1994.
He denies the charges and says his father was the real killer, who then turned the .22 Winchester rifle on himself.
Mr Bain was convicted of the murders in 1995, but in 2007 the Privy Council quashed the convictions. A retrial was subsequently ordered.
Earlier on Thursday, one of David Bain's uncles told of visiting his nephew in prison and asking him if he murdered his family.
Michael Bain said he visited Dunedin Prison a week after the killings and took it upon himself to pose the question to David because no-one else in the family had done so.
In the High Court in Christchurch on Thursday, he said David did not answer him "yes" or "no", and would say only that he had given his side of the story to the police and he was sticking to that.
Robin Bain was Michael's eldest brother.