The man who murdered British backpacker Grace Millane in Auckland, New Zealand, has begun an appeal against his guilty verdict and jail term.

In opening remarks at an Auckland court hearing on Thursday, defence lawyer Rachel Reed said she would not try to to justify his actions. “I do not in any way seek to condone or excuse his actions after Miss Millane’s death,” she said, according to the New Zealand Herald. “I cannot and will not do so – they are inexcusable. This appeal is about whether the trial process miscarried.”

In November, a jury took just five hours to unanimously agree that the accused, whose name is suppressed, murdered Millane in his hotel room after the pair met on a date in Auckland in December 2018.

Her death by strangulation during sex provoked a debate in New Zealand and Britain about reliance on arguments of so-called “rough sex” as a defence for murder. It also prompted an outpouring of grief in New Zealand and vigils for the young woman that were attended by thousands across the country.

In February, a judge sentenced the 28-year-old to life in prison with a minimum non-parole period of 17 years. His lawyer indicated in March that he would appeal.

“Sometimes trial lawyers consider that it may be helpful for another lawyer to review afresh the trial and sentence process when an appeal is being considered,” the man’s trial lawyer, Ian Brookie, said in a statement in March. “That has been recommended to my client and has happened here, with our assistance.”

Delivering the life sentence, Justice Simon Moore said the crime had shocked New Zealand and the killer showed no remorse. “Manual strangulation is a particularly intimate form of violence … cold-blooded,” Moore said. “Your actions reveal a complete disregard for your victim.

“You didn’t ring an ambulance, or call the police, instead you embarked on a well-planned and sustained and coordinated course of action to conceal any evidence of what had occurred in your room.”

Millane, 22, from Essex, arrived in New Zealand in November 2018 as part of a round-the-world trip. She met the man who killed her on the dating app Tinder.

After her death, the man buried her body in a suitcase in the Waitakere ranges, a bushland area west of New Zealand’s largest city. She was found eight days after she died.

During the sentencing hearing Millane’s mother, Gillian Millane, read out a victim impact statement via videolink describing the destruction Millane’s killer had wrought on her family.

“The tears I shed are never-ending, at the thought of never having the chance to be able to kiss my darling Grace goodbye,” she said. “Grace was never just a daughter, she was my friend, my very best friend.

“I torment myself over what you did to my Grace, the terror and pain she must have experienced at your hands. As a mother I would have done anything to change places with her.

“I should have been there, but she died terrified and alone in a room with you.”

Thursday’s hearing will take place in front of three justices in the court of appeal in Auckland. The prosecutor from the man’s original trial, Brain Dickey, will appear for the Crown.