The man found guilty of killing British backpacker Grace Millane has started the process of appealing against his conviction and jail sentence, according to his barrister.

Rachael Reed QC, his lawyer, said that an appeal has been lodged in the New Zealand Court of Appeal.

The 28-year-old man, who cannot be named for legal reasons, was convicted of strangling Ms Millane to death a day before her 22nd birthday in December 2018.

Last month, he was handed a minimum sentence of 17 years for the crime, which he must serve before he can seek parole.

His defence lawyers had asked for a 12-year sentence.

Grace Millane trial: British backpacker 'murdered by Tinder date' Show all 11 1 /11 Grace Millane trial: British backpacker 'murdered by Tinder date' Grace Millane trial: British backpacker 'murdered by Tinder date' David and Gillian Millane (second from right and right) arrive at Auckland High Court, in New Zealand, on Wednesday, 6 November, 2019, for the start of their daughter Grace Millane's murder trial. The body of the 21-year-old British backpacker was found in a forest area near Auckland on 9 December, 2018 - a week after she was last seen. Michael Craig/NZ Herald via AP Grace Millane trial: British backpacker 'murdered by Tinder date' The parents of Grace Millane, David and Gillian Millane, arrive at Auckland High Court with Detective Inspector Scott Beard, 6 November, 2019. Phil Walter/Getty Images Grace Millane trial: British backpacker 'murdered by Tinder date' Candles and flowers are laid next to a photo of Grace Millane during a vigil at Civic Square Park in Wellington on 12 December, 2018. Marty Melville/AFP/Getty Grace Millane trial: British backpacker 'murdered by Tinder date' Defence lawyers Ian Brookie (left) and Ron Mansfield (right) arrive at Auckland High Court, 6 November, 2019. Fiona Goodall/Getty Images Grace Millane trial: British backpacker 'murdered by Tinder date' Crown prosecutor Brian Dickey arrives at Auckland High Court, 6 November, 2019. Phil Walter/Getty Images Grace Millane trial: British backpacker 'murdered by Tinder date' Auckland High Court Fiona Goodall/Getty Grace Millane trial: British backpacker 'murdered by Tinder date' People place candles and flowers next to a photo of Grace Millane during a vigil at Civic Square Park in Wellington on 12 December, 2018. Marty Melville/AFP/Getty Grace Millane trial: British backpacker 'murdered by Tinder date' David Millane speaks at a press conference in Auckland, New Zealand, on 7 December, 2018, while his daughter Grace Millane is still missing. Doug Sherring/NZ Herald via AP Grace Millane trial: British backpacker 'murdered by Tinder date' Undated photo issued by the Lucie Blackman Trust of 22-year-old British backpacker, Grace Millane, who is missing in New Zealand. PRESS ASSOCIATION Photo. Issue date: Friday December 7, 2018. Ms Millane, from Essex, was on a year-long round-the-world trip, but was last seen in Auckland at 9.41pm at the Citylife Hotel on December 1. See PA story MISSING Auckland. Photo credit should read: Lucie Blackman Trust /PA Wire NOTE TO EDITORS: This handout photo may only be used in for editorial reporting purposes for the contemporaneous illustration of events, things or the people in the image or facts mentioned in the caption. Reuse of the picture may require further permission from the copyright holder. Lucie Blackman Trust Lucie Blackman Trust/PA Grace Millane trial: British backpacker 'murdered by Tinder date' CCTV still image issued by Auckland City Police of one of the last sightings of Grace Millane. Auckland City Police/PA Grace Millane trial: British backpacker 'murdered by Tinder date' BEST QUALITY AVAILABLE Undated handout photo issued by Auckland City Police of Briton Grace Millane, 22, who is missing in New Zealand. PRESS ASSOCIATION Photo. Issue date: Thursday December 6, 2018. Ms Millane, who is reportedly from Essex, was last seen in Auckland on Saturday night and police said they are growing increasingly concerned for her welfare. See PA story MISSING Auckland. Photo credit should read: Auckland City Police/PA Wire. NOTE TO EDITORS: This handout photo may only be used in for editorial reporting purposes for the contemporaneous illustration of events, things or the people in the image or facts mentioned in the caption. Reuse of the picture may require further permission from the copyright holder. Auckland City Police/PA

The man's defence that Ms Millane had died during "rough sex gone wrong" was rejected by a jury in November 2019.

Women's rights groups are now seeking to change the law by bringing an end to the "rough sex" defence, which is thought to have been on the rise in recent years.

Ms Millane had been on a year-long backpacking trip when she was killed by the man in a hotel room in Auckland.

He then put her body in a suitcase and buried it in a mountainous area outside the city.

At his sentencing, Gillian Millane told the killer that her daughter had "died terrified and alone in a room with you ... all her dreams and aspirations taken.”

When he sentenced the man for murder, Justice Simon Moore told him that his conduct “underscores a lack of empathy and sense of self-entitlement and objectification".

Speaking after the sentencing, Detective Inspector Scott Beard of Auckland City Police called the death "senseless and needless".