Grace Millane's former partner: She asked me to choke her during sex

Stephen D'Antal in Auckland, New Zealand

British backpacker Grace Millane belonged to BDSM dating sites and allowed a former partner to choke her during sex, a court has heard.

An ex-boyfriend of the university graduate from Essex said they had used a system of safe words and signals to make sure she was never in danger.

A statement from the man, whose identity is protected, was read to the jury at the trial of a 27-year-old New Zealander accused of strangling Grace to death at the end of a Tinder date.

The defendant, who also cannot be named for legal reasons, says Miss Millane died accidentally during consensual sex at his apartment in Auckland last December after she asked him to put his hands on her neck during rough sex.

Miss Millane's former partner said in a statement read to Auckland High Court: "When we researched it we knew the word was asphyxiation.

"Grace and I discussed keeping hands wide and on the side of the neck, never on the front.

"Grace and I would have a safe word most of the time which we had discussed, something like "turtle" or something ridiculous. Grace and I used a tapping practice too. If Grace tapped me three times then it would stop.

"Grace would tap out maybe one in four times.

"Grace would be sure to do this and I trusted that anytime it was too much for Grace she would do this. Grace and I were careful to discuss not only the physical but the psychological aspects to practising BDSM."

Statements from police revealed that Miss Millane had been active on BDSM dating site Whiplr an hour before meeting the defendant outside a central city casino.

Defence barrister Ron Mansfield told the jury: "All the evidence shows that Miss Millane was a loving, bright, intelligent young woman and she was.

"That is her reputation and that should be her reputation and her memory at the start of this trial and at the conclusion if it.

"The fact that we need to discuss with you what she liked to do in the bedroom should have no impact on her reputation at all."

But, he said: "It's important that we are fully informed. It's not the time for embarrassment or immaturity.

"If this couple engaged in consensual sexual activity which included pressure being applied to her neck with her consent and that went wrong, that is not murder.

"Death through this mechanism may thankfully be rare but it does happen and sadly it happened here."

Mr Mansfield said the defendant admits Grace died from pressure he placed on her neck but said expert evidence was consistent with his account that it was consensual, not violent.

In a police interview, the trial heard last week, he said he only realised Grace was dead when he found her lying on the floor but admits then cramming her body into a suitcase which he buried in a shallow grave in the woods.

Mr Mansfield said his failure to call for help, disposal of Grace's body and lies to police were due to panic.

"He may have thought he wouldn't be believed," Mr Mansfield told the jury, "but don't prove him right."

The court also heard that Miss Millane had drunk so much that night that her heart may have gone into a "terminal tailspin" when she was choked during sex.

Pathologist Dr Fintan Garavan, appearing as a defence witness, told the jury a combination of obstruction of the blood flow, pressure on her nervous system and being drunk meant she might have died quickly.

There were no signs of her having struggled and her plight "would not be obvious to a person nearby unless you know what you are looking for," he said.

Defence barrister Ian Brookie said Miss Millane had drunk four mango cocktails, one tequila shot, two whisky cocktails herself and shared three half litre jugs of margheritas and sangria with her alleged killer during their night out.

Dr Garavan said the alcohol, in conjunction with the choking, was "an iceberg making its way into the shipping lane".

"It very likely has become an important indirect player in causing death," he said, explaining that being drunk could turn off a "safety valve" which would normally trigger someone to fight for breath.

Dr Garavan, who examined hundreds of photographs of Grace's body, agreed the primary cause of death was asphyxiation, which he said would have required just one kilogram of pressure.

But he said the absence of deeper haemorrhages in the neck muscles, fractures or scratches to the skin "would favour consensual" choking.

The court previously heard from a woman who met the defendant on Tinder, who said he suffocated her during a sex act.

Another woman, a waitress, previously told the jury she had asked the defendant to choke her during sex because it was "a preference of mine", saying it was consensual.

The defendant has previously told police he buried Ms Millane in a shallow grave in the woods before taking dozens of pills in a suicide attempt.

The trial continues.