Nai Yin Xue told friends he had no problems keeping his young wife because he would kill her if she ever left him, a court has been told.
Nai Yin Xue, 55, is on trial for the murder An An Liu, 28, in New Zealand in September 2007, before abandoning their daughter in Melbourne.
The couple's daughter Qian Xun Xue, then aged 3, was found alone at a Melbourne railway station a few days before her mother's body was discovered in the boot of a car in Auckland.
Mr Xue was later apprehended in the United States. He denies the murder charge and is being tried at the High Court in Auckland.
Crown witness Jian Zhang told the court on Thursday Mr Xue and Ms Liu were married after the accused suggested he would a good candidate to help the Chinese-born woman stay in New Zealand.
Ms Zhang said friends asked Mr Xue if he ever worried about having such a big age gap with his wife.
She told the court Mr Xue said no, because he would kill her if she ever left him.
Ms Zhang says Ms Liu told her he had pointed a gun at her before.
But the defence objected to that evidence about the gun and Justice Williams cautioned the jury that it was not integral to the Crown's case.
Wife thought she was being followed - witness
Another Crown witness told the court Ms Liu believed Mr Xye had been following her when she was staying in a safe house.
Qu Zhen, a former social worker, says she helped Ms Liu into a safe house after an incident in which she was beaten by Mr Xue.
Ms Zhen says on one occasion An An Liu phoned her from the safe house, very frightened, saying she had gone outside and a car had been following her very slowly. She believed Mr Xue was in the car.
Ms Zhen says Ms Liu's biggest fear was losing custody of the couple's child.