By 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 he 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."