Warning: This story and related coverage of the trial contain graphic details that may be distressing.
A forensic scientist who tested blood flecks on a fridge has told a jury there is "extremely strong scientific evidence" the DNA identified belonged to Grace Millane.
Institute of Environmental Science and Research scientist Turlough Thomas-Stone told the court this afternoon the DNA was 500,000 million times more likely to belong to Ms Millane than a person selected at random in the New Zealand population.
Mr Thomas-Stone also tested swabs from probably blood stains in a suitcase in a wardrobe and received strong scientific results that showed the DNA was Ms Millane's.
Under cross examination by Mr Brookie, the expert told the court no male DNA was found under Ms Millane's fingernails.
A 27-year-old, who cannot be named, is on trial before a jury of seven women and five men in the High Court at Auckland this month.
It's the Crown's case he murdered Ms Millane in his CityLife apartment after meeting for a Tinder date in Auckland's CBD last December.
The man's defence team is arguing the British backpacker's death is accidental after rough sex with her consent and encouragement.
Earlier, ESR scientist Dianne Crenfeldt examined his apartment, where it's agreed Ms Millane died on the night of 1 to 2 December last year.
This morning she told the jury luminol testing identified two probable blood stains between the bed and the wardrobe; one 70cm and another 30cm in diameter.
She said the larger stain had circular smearing within it, while the smaller one had a more defined, circular shape, consistent with the base of a bucket, and surrounding spots showed blood was likely dripped onto the carpet.
The court has heard no bucket was found when police searched the apartment.
Ms Crenfeldt couldn't determine how the blood had dripped but said it could been cast off from a body or fallen from a mop after being diluted with water.
She said the staining supported a theory that a clean up had occurred but could not say how old the blood was or when any cleaning may have occurred.
"The shape of probable blood staining showed strong support for the proposition that clean up of blood had occurred in this area."
The jury has heard the defendant told police he fell asleep in the shower after having sex with Ms Millane before getting into bed to sleep.
He said he woke up the next morning to find Ms Millane dead, and bleeding from the nose, on the floor of his bedroom.
This morning the court heard luminol testing showed blood smearing on the carpet which indicated movement around the room when it was still wet.
"It's the same with the footprints around the room which show somebody with blood on their feet moved around the room and transferred blood to these areas."
The court heard this blood wasn't visible to the naked eye but luminol testing, which is extremely sensitive, had identified the affected areas.
But Ms Crenfeldt said when the carpet was lifted, there was blood visible on the underside of the carpet, as well as on the underlay and the concrete floor.
Yesterday, the scientist said she was asked to examine an Adidas sports bag and a black suitcase found in a wardrobe that were of particular interest to police.
"I was advised that these bags had been seen on CCTV being removed from the building at the time of interest.
"I was also advised that the black sports bag, along with the bedding, had been taken to a dry cleaners where it had been cleaned."
Ms Crenfeldt said there was no blood on the Adidas bag but stains were found in the carpet, on the fridge and on the suitcase.
The jury has watched CCTV footage that tracked the defendant and Ms Millane's movements around Auckland's CBD on their date.
They bar hopped for three to four hours after meeting at the Sky Tower; drinking cocktails, tequila and jugs of margarita and sangria.
This afternoon forensic toxicologist Diana Kappatos told the court she tested a blood and stomach sample from Ms Millane for the presence of alcohol.
She told the court the alcohol level found in the blood was 106 milligrams per one hundred millilitres of blood.
Ms Kappatos told the court microbial action in the body may increase or decrease alcohol concentration so she couldn't be certain her result was the level present at the time of Ms Millane's death.
There were no drugs detected in Ms Millane's body, the court heard.
Ms Millane's parents David and Gilliane have been in court again today to hear the forensic evidence and cross-examination by the man's lawyer Ian Brookie.
The trial before Justice Moore and a jury is set down for four weeks but may finish earlier.