"Just before we start do you mind if we have karakia before we start?" Dennis said, before reciting a Maori prayer at the start of the interview.
At the time, Dennis, who has more than 30 years of police experience and is the National Maori Strategic Advisor, was being investigated but not under arrest.
The interview was also conducted with Dennis' wife, and counsel Stephen Bonnar QC by his side at the Ponsonby Police Station.
Dennis, who said he didn't know the teen well and was a stranger to the girl's family, was made aware of the relationship after attending a fight between the two families at an Auckland park in March 2015.
Just days later the teen's mother filed a formal complaint with police, alleging her son was having a sexual relationship with a minor.
Dennis, who has never worked on a child protection team or sexual assault team, said he felt an "obligation" to his duty to intervene and help the boy's family.
"We'll I'm not to drop the ball on the family because no one actually wanted to deal with this complaint," he said.
"Now the police, CYFS, our approach was very limp, and for me, you know, when the family, when these two kids needed some help I wasn't gonna drop the ball on them."
However, Pratt was quick to point out the investigation had only just started.
"Well it begins when the families are in feud - it begins when the families can see some danger with their boy. In particular with [the teen] having sex with a 15-year-old girl," Dennis replied.
"[The] trust and confidence the family had in the investigations team, especially in Neil [Detective Sergeant Hilton], wasn't flash," he added.
Dennis said the teen's alleged underage sex was "causing a bit of carnage" and led to the boy's mother laying the police complaint in a "bloody desperate move".
He also laid some blame for the situation on the girl's mum.
"I consider the two kids to be the victims in this situation - because it's being facilitated by the girl's mother," he said
Hilton decided against laying charges against the teen.
As inter-family angst grew over the teenage couple's relationship, Dennis organised a "mock arrest" to scare the boy off the relationship, the court has heard.
The teen was processed at the Auckland Central Police Station on May 5, 2015 as though he had been arrested by Dennis and Perry, the duty custody sergeant.
Dennis also gave the teen an ultimatum - to either go to Australia and start a new life or be charged for statutory rape, the court has heard.
Dennis said in the interview that he was teaching the boy "a bit of choices and consequences".
The teen was then sent to Australia, but on June 10, 2015 tried to "escape" back to New Zealand.
However, Dennis "swung into action" and arranged for armed police to usher the teen off the aircraft when his flight arrived in Auckland, the court has heard.
Dennis told the boy not to come back to the country until he was 18 and placed him on another flight to Australia, the court has heard.
While back in Sydney, the teen fled to associates of his girlfriend's mum and later reported the incident to New South Wales Police on June 17, 2015.
Dennis, who belongs to Rongowhakaata and Ngati Porou iwi and was also the chairman of Te Puea Marae in Mangere, was stood down from his duties in September 2015.
He argues his actions were consistent with Maori cultural customs, police strategy to keep young Maori out of prison, and the law.
The trial continues.
