Daughter heard threats to kill sea lion

A man accused of stabbing to death a sea lion pup became the focus of the police investigation after his daughter outed him as a suspect, a court has heard.

The woman's role only emerged under cross-examination during the trial before the Dunedin District Court, which began yesterday.

The witness admitted she was aware there was a reward for information on the death of Rua the sea lion but told counsel Judith Ablett-Kerr QC she had not claimed the cash.

"It wasn't about the reward,'' she said.

The 54-year-old defendant, who has interim name suppression, has pleaded not guilty to wilful ill-treatment of an animal and perverting the course of justice.

On November 5, 2016, Department of Conservation biodiversity ranger Jim Fyfe was called to Portobello after hearing of the animal's death.

He found Rua behind some rocks at Quarantine Point and initially thought she had been shot, Crown prosecutor Craig Power told the jury in his opening address.

However, when the carcass was examined by experts at Massey University, they found two stab wounds.

A scientist is expected to tell the jury the injuries were inflicted by a smooth-edged blade at least 15cm long.

Police executed a search warrant at the defendant's home while he was on holiday and seized two knives and a bayonet from his kitchen.

That bayonet, the expert will say, was consistent with the wounds found to Rua.

A forensic scientist from the United States analysed the weapon and found a combination of human and sea lion DNA, Mr Power said.

The defendant's daughter had been living with him for several months before police visited the home.

She said the man had vowed to kill the sea lion, which was eating fish he was trying to catch and ripping holes in his nets.

"He said it in front of my children. They were concerned about it,'' she said.

Ms Ablett-Kerr suggested the woman had brought the spotlight on to her father because there had been friction in the domestic environment.

The defendant, the lawyer submitted, had asked his daughter to leave the home because of the screaming matches she had with her daughter.

"He never asked me to move out. I'm sure of it,'' the woman said.

The defendant's ex-partner told the court yesterday, she had been in a relationship with the man for a few weeks before the death of Rua.

She described him as "extremely angry'' that he was missing out on catching salmon because a marine mammal was interfering.

"He was going to kill it or poison it,'' she said.

Ms Ablett-Kerr said the police investigation into the slaying was flawed from the outset because it focused solely on her client.

Relations between the officer in charge of the case and the defendant became strained, the court heard.

The pair spoke on the phone on February 27, 2017 during which the defendant allegedly accused him of cheating on his wife and said he would inform her.

"Don't threaten me,'' the officer said.

"It's not a threat, it's a promise,'' the defendant allegedly responded.

Ms Ablett-Kerr said the suggestion that that was an attempt to pervert the course of justice was "rubbish''.

"Rather the opposite. There was a volatile plea for a fair inquiry for a man who thought he was the victim of a witch hunt,'' she said.

Ms Ablett-Kerr warned the jury to guard against an emotional response when considering the evidence.

"Emotion is the enemy of good justice.''

The trial, before Judge Michael Crosbie and a jury of nine women and three men, is expected to last a week.