An hour later, he went to reception with a serious head injury and asked for help. He died in hospital soon after.
Nattrass-Berquist and Wallace-Loretz were identified by members of the public after police released images recorded by the motel's CCTV cameras.
Officers said the pair had been avoiding arrest since images of them were published.
Detective Inspector Scott Beard could not comment further on the investigation or charges as the matter was now before the court.
"Police would like to thank members of the public who have assisted the investigation," Mr Beard said.
Ihaia Gillman-Harris funeral service will be held tomorrow morning.
"It's a relief to be able to give Mr Gillman-Harris' family the news that we have arrested these two people."
Later in the day, Mr Gillman-Harris' nephew Ihaia Harris posted a message on his Facebook page about the arrests.
The CCTV footage of Leonard Nattrass-Berquist and Beauen Wallace-Loretz at the motel. Photos / Supplied
"They are now in police custody. Thank you for your efforts, New Zealand," he wrote.
It was not clear how Mr Gillman-Harris met the teenagers, but it is understood they were there for a prearranged meeting.
Ihaia Harris told Maori Television's Te Kaea programme that Mr Gillman-Harris' body had been released to his family and lay in state at a Henderson property.
Mr Gillman-Harris was taken yesterday to Piki Te Aroha Marae in Rahiri, Northland, for his tangi, which will end with a funeral service tomorrow morning.
A friend paid tribute to Mr Gillman-Harris on an online memorial website.
"I was shocked and saddened to hear of Ihaia's death," the friend wrote. "Although I have not been in touch for many years, I have great memories of the Harris family, who were neighbours in Tokoroa during the 1970s.
"I remember their wonderful singing and sense of fun. There was a lot of laughter."