The expert who led the scientific investigation of the apartment where young English woman Grace Millane was allegedly murdered has started testifying in Auckland High Court.

Scientist Dianne Crenfeldt, from the Institute of Environmental Science and Research (ESR), told the jury she had located two approximately circular probable blood stains between the accused's bed and a wardrobe.

The smaller of the stains was more circular and "could have come from a bucket", Ms Crenfeldt said.

She added: "The shape of the probable blood staining and the presence of blood on the floor provided strong support that clean up of blood had occurred in this area."

The Crown has alleged the defendant, who cannot be named due to a suppression order, murdered the young woman from Wickford, Essex, and shoved her body inside a suitcase before burying her in a forested area outside Auckland.

The defence claims the death, on either December 1 or December 2 2018, the date of Ms Millane's 22nd birthday, was accidental.

On Thursday, security footage played for the jury showed Ms Millane, who was on a round-the-world trip, visiting a number of bars in the city centre with the accused 27-year-old, where they drank alcohol.

Ms Millane's friend, Ameena Ashcroft, said she "thought something was out of place" when the young woman sent a series of messages on December 1 2018 in which Ms Millane described wanting to "get smashed" with the man she met on Tinder.

Security footage showed the pair kiss repeatedly at the Bluestone Room before walking arm-in-arm a short distance into the lobby of the CityHigh hotel, where the defendant was staying.

Ms Millane was shown to follow the defendant out of the lift at 9.41pm.

It was the last time she was seen alive.

Gillian Millane, the mother of the deceased woman, left the court in tears as detective Samuel Luker described a series of photographs found on the defendant's phone.

Those photographs taken in the early hours of December 2 2018 showed intimate photos of a woman's body, the detective said, which the Crown has alleged were taken of Ms Millane after her death.

The defendant, wearing a navy blue suit and black shirt, did not react as Gillian Millane walked out of the courtroom.

Data from the man's phone showed he had used Google to browse websites for large duffel bags, suitcases and car hire.

The defendant's phone was also used to search for "flesh-eating birds" and "are there vultures in New Zealand?" days later, on December 5 2018.

Records showed the defendant had searched online for "the hottest fire", "large bags near me" and "Waitakere Ranges" - where Ms Millane's body was later found contorted inside a suitcase on December 9 2018 - before going on another Tinder date later that day.