A former teacher of David Bain's sister Laniet said he was not sure whether her stories, about giving birth to a black child and having an abortion, were true.
On the 34th day of the Bain murder trial in the High Court at Christchurch, witness Paul Hewson said that between 1993 and 1994 Laniet told him that she had been raped while the family lived in Papua New Guinea and had given birth to a black child.
Another time she told him that she had an abortion, the Christchurch Court News website reported today.
David Bain denies murdering five members of his family, including Laniet, in 1994. Bain's defence team maintains the father, Robin Bain, killed his wife and three of his children before turning a rifle on himself.
Laniet also said she had attempted to kill herself, but her older sister Arawa saved her, Mr Hewson said.
She also told him in late May or early June 1994 that she had run short of money and was working as a prostitute.
He said she seemed happy and full of life when he last saw her.
Mr Hewson also taught Bain's 14-year-old brother Stephen and said he was strong and robust, tenacious and physical. He was gangly with big hands and feet - all arms and legs in the physical education class.
Mr Hewson knew Bain through an athletic club and told defence counsel Michael Reed QC that he was polite and likeable.
He said all the Bain family were pleasant and friendly.
Mr Reed told him that something did happen in Papua New Guinea, and that Laniet kept a photograph of a child in her room.
Also testifying today was a prison officer, Thomas Samuel, who told of strip searching Bain after his remand in custody, three days after the killing of five family members.
He said Bain had scratch marks and bruises around the right shoulder and upper arm area "consistent with clawing or grappling with clothing".
The clawing was consistent with fingers evenly spaced, and the bruises were consistent with pushing.
Mr Reed cross-examined Mr Samuel and pointed out he had not given evidence at Bain's first trial and had come forward only in 2007.
Mr Reed said Bain was examined by a doctor on the day of the deaths and there were no marks on his chest.
A retired bank officer, John Boyd, the brother-in-law of Bain's mother Margaret, also gave evidence about the Bain family finances. Details were suppressed.
He said police eventually told the family they had to withdraw the security guards at the family's Every St house.
There was concern that it was a fire risk and that people might "poke around it".
The valuation of the property was higher without the house.
David Bain told him he had no feeling for the house at all and was happy for it to be burnt, which was done, he said.
