Grace Millane‘s killer was “quite taken by morbidity” and tested the “most believable” theories for her death, another woman who went on a date with him hours after the murder has said.

In a column for Newshub, the woman, who gave evidence during the trial, described going on a date with the 27-year-old man, who has not yet been named, on 2 December after they met on dating site Tinder.

A day before, he had gone on a date with British backpacker Ms Millane and killed her either that night or in the early hours of the next morning, the day of her 22nd birthday.

“My instincts told me something was not right with this man and, while it took me a long time to write this, I want to share my experience so other women can remove themselves from situations they feel unsafe in,” the woman wrote.

The woman said she was struck during their date in the Auckland suburb of Ponsonby by how clean the killer looked, his “huge eyes” and how “intense” he became when talking about venomous snakes.

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

She said the man referred to buying a suitcase – in which Ms Millane’s body was later found buried in a shallow grave outside Auckland – but was frustrated it was not large enough to fit his sport equipment.

The killer mentioned his best friend, a Crown prosecutor, was moving from Sydney to Auckland, which interested his date, who referred to her previous career as a court reporter, including on a murder trial.

He then said something that seemed strange to her: “It’s funny how guys can make one wrong move and go to jail for the rest of their lives.”

He continued: “I heard of this guy whose partner asked to have rough sex with him involving some sort of strangulation and suffocation but it went wrong and the guy couldn’t revive her and she died. He got done for manslaughter but it was really tough for him to see this woman he loved dying.”

She wrote: “In hindsight, it was as if he was using this date to process what he’d done in a rather roundabout way – his brain needed to get it out but his mouth held him back.

“Was he testing theories on me to see which version seemed most believable?”

The woman said she was careful to never leave her drink with the killer, adding: “For some reason, I felt like he was the type of guy who would spike it. I felt bad for thinking that though.”

As they left the venue she lied to him about the location of her car because she “felt unsafe with him”.

Grace Millane: Alleged murderder describes forcing British woman's dead body into suitcase

The 27-year-old man, whose name is protected by a court order, was found guilty on 22 November of strangling Ms Millane.

The jury of seven women and five men returned a unanimous verdict after just five hours’ deliberation at Auckland High Court.

The Crown successfully argued the man strangled her and shoved her body inside a suitcase before burying her in a forested area outside Auckland.