The man who murdered a British backpacker he met on a dating app and dumped her body in a forested area in New Zealand has lost an appeal against his conviction and prison sentence, a court said.

The 28-year-old man who strangled Grace Millane appealed to the New Zealand Court of Appeal in August but it found against him on Friday, according to court documents seen by the PA news agency.

Justices Stephen Kos, Mark Cooper and Patricia Courtney said the Auckland murder was “committed with a high degree of callousness” due to the man failing “to call for assistance, searching on the internet for methods of body disposal … taking steps preparatory to disposing of the body and going on another date while Ms Millane’s body remained in his room”.

The judges also found his sentence was not “manifestly unjust”.

A New Zealand Supreme Court spokesman said the court had granted an interim order suppressing the man’s identity, which would otherwise have been made public following the loss of his appeal.

The man was convicted of murdering Ms Millane by strangling her in a hotel in Auckland after meeting her via Tinder on December 1, 2018 – the day before her 22nd birthday.

Ms Millane’s body was later found in a suitcase buried in a forested area outside the city.

In February the man was jailed for at least 17 years for the murder.

He claimed Ms Millane, who was from Wickford in Essex, died accidentally after the pair engaged in rough sex that went too far.

A jury in November 2019 rejected that argument and found the man guilty.

Murder typically comes with a life sentence in New Zealand. Prosecutors successfully argued the man must serve 17 years before becoming eligible for parole.

In sentencing, Justice Simon Moore told the murderer his actions amounted to “conduct that underscores a lack of empathy and sense of self-entitlement and objectification”.

On Friday, the judges upheld that saying: “Ms Millane was particularly vulnerable, being intoxicated, in a strange apartment, naked, in the arms of a comparative stranger with whom she thought she could trust, and with his hands around her throat”.

Ms Millane’s father David Millane, 62, died last month after a battle with cancer, New Zealand Police said at the time.

On Friday the force issued a statement from the Millane family, who said they were “pleased at the outcome that has been reached” in the loss of the appeal.

The family thanked the police, judges, prosecutors and the people of New Zealand.

They added: “Grace was a kind, fun-loving daughter, sister, granddaughter, niece, aunty, cousin and friend with her whole life ahead of her.

“She was enjoying the first of what would have been a lifetime of adventures before her life was so cruelly and brutally cut short by her murderer.

“Her sense of fun, her sense of adventure, her love of travel and exploring, along with her ability to light up any room she walked into it with her generosity of spirit, are memories we as a family cherish and how we will forever remember her.

“Although the focus will inevitably be on the outcome of today’s legal process, as a family our hearts and our love will always be with our beautiful Grace.

“Grace, you are, and will always be, our sunshine.”