Mark Lundy admitted to police it looked "a little bit funny" the amount his wife was insured for had more than doubled to $500,000.
Mr Lundy, 56, is accused of murdering his 38-year-old Christne Lundy and seven-year-old Amber. Their bodies were found in their Palmerston North home on 30 August 2000; the Crown claims Mr Lundy killed his wife for her insurance money and Amber because she saw what he was doing to her mother.
He is on trial in the High Court in Wellington, where the jury is today being shown his interview with Detective Inspector Stephen Kelly, who in 2000 was a detective sergeant in Palmerston North.
The trial has previously been told the Lundys had increased their life insurance from $205,000 to $500,000 soon before the deaths, but that Mr Lundy had believed the lower amount would be paid out as they had not heard from their insurance broker Bruce Parsons that it had gone through.
However, in the interview with Mr Kelly, Mr Lundy said Mr Parsons had been to see him and said the higher amount would apply.
"It makes it look a little bit funny," he said.
The couple also had mortgage insurance with Sovereign, so their mortgage would be paid off.
Lundy felt like 'absolute wreck'
Earlier in the 14 September interview, Mr Lundy said he felt like "absolute shit".
"My life is just destroyed. Honestly, I am an absolute wreck."
Mr Lundy said he had to force himself to do something every day and that he hated going out in public as he was scared he would break down when people offered him sympathy.
Mr Kelly asked Mr Lundy what he believed had happened and after initially saying he had no idea, he then suggested it was a burglary gone wrong.
His hope was "neither of them saw each other die, and they died quickly, and that's what's getting me through".
"Who would take the life of my beautiful little girl especially," he said, his voice cracking.
Mr Lundy said in the interview he and his wife had sex every six or seven weeks.
"Neither of us had a tremendous sex drive, to be honest."
He had flirted with other women but never had an affair as he loved his wife too much for that, he said.
The pair had tried unsuccessfully for another child after Amber but were unable to have one so had started using birth control.
Mr Lundy appeared surprised when told his wife had a pregnancy kit next to her bed.
"Shit. I didn't know that," he said. "God. Oh Jesus."
Earlier today, defence witness Professor Michael Horowitz, director of the Endocrine and Metabolic Unit at the Royal Adelaide Hospital, gave evidence around what he believed to be the time of death of Mrs Lundy and Amber.
The pair were known to have bought McDonald's at 5.45pm but their stomach contents revealed fish and chip-style fries - not the shoestring ones common to McDonald's.
Mrs Lundy's stomach also had crinkle cut potato chips in it.
Pathologist James Pang, who conducted their autopsies, has already given evidence he did not believe digestion had occurred due to their stomachs being full, a lack of gastric odour and a lack of digestion.
But last week he said the only thing he could be certain of was that they died between when someone last spoke to Mrs Lundy about 7pm on 29 August and when her brother, Glenn Weggery, found their bodies about 9am on 30 August.
But Prof Horowitz said gastric emptying was likely to have started one to two hours after they last ate, meaning they were killed within one to two hours of doing so.
He agreed with prosecutor Ben Vanderkolk what was not known, however, was what their last meal was and what time it was eaten.
The trial, before Justice Simon France and a seven-man, five-woman jury, today entered its seventh week.
*Clarification - For the avoidance of doubt, please note that Radio New Zealand reporter Sharon Lundy is no relation to Mark Lundy.