Millane died in December after meeting the man online on the eve of her 22nd birthday, going out for drinks with him then returning to his hotel apartment in central Auckland.

Prosecutors said the man strangled Millane. Defence lawyers claimed the death was accidental after the pair engaged in consensual erotic choking that went too far.

But the jury did not buy the defence. After the three-week trial at Auckland High Cout, they deliberated for about five hours on Friday afternoon before returning the guilty verdict.

The 27-year-old man, whose name is suppressed by court order, is due to be sentenced February 21.

Millane's parents, Gillian and David, who were present at the trial since it began on November 4, tearfully told media the verdict was welcomed by friends and family alike.

"It will not reduce the pain and suffering we have had to endure over the past year," David Millane said.

"Grace was taken in the most brutal fashion a year ago and our lives have been ripped apart."

He said that "Grace was our sunshine and she will be missed forever".

Millane had been travelling through New Zealand as part of a planned yearlong trip abroad after graduating from university.

After the man killed Millane, he stuffed her body into a suitcase, drove to the Waitakere Ranges forest and buried her in a shallow grave, where police found her body a week later.

Her death shocked many in New Zealand. Hundreds of people attended candlelight vigils and Prime Minister Jacinda Ardern spoke about New Zealanders feeling "hurt and shame" that she was killed in their country.

Justice Simon Moore told jury members before they delivered their verdict that they had to be certain the man had murderous intent when he put his hands on Ms Millane's neck during sexual intercourse to convict him of murder.

He further asked them to consider if the accused was willing to take the chance of Millane dying due to his actions.

"If yes, then (the defendant) is guilty of murder," the judge said.

"In other words, (he) must have appreciated Ms Millane's death was a likely consequence... but was willing to run that risk."

The court had been told Millane had an interest in BDSM, with a previous sexual partner testifying they had used safe words and physical tapping to indicate when physical pressure became overwhelming.

The jurors heard from forensic experts who examined the accused's apartment for blood stains as well as Millane's body after her death.

They were also shown footage of the woman and the defendant drinking at various bars throughout Auckland and kissing before they returned to his apartment.

Video from the elevator of her exiting on the third floor marked the last recorded time Millane was seen alive.

Australian Associated Press