A 23-year-old man accused of murdering his partner told police she died during an sex act, a court has heard.
Dawid Lukasz Mietus, of Drumalane Park in Newry, was charged with murdering 20-year-old Patrycja Wyrebek.
Ms Wyrebek's body was found in her home on Sunday in Newry.
Mietus, who is from Poland, was arrested on suspicion of the murder of his partner hours later.
The accused told police that he and Ms Wyrebek, who had been partners for seven or eight months, had a shared interest in erotic asphyxiation.
Jonathan Browne, a barrister for the accused, told Newry Magistrates' Court that Mietus claimed his partner had introduced him to that form of sexual intercourse.
"He said that on that night they both drank a large amount of alcohol, a bottle of wine each and vodka after," Mr Browne added.
"He said the deceased became unresponsive during consensual sexual intercourse and that was at a time they were practising consensual erotic asphyxiation.
"The normal agreement between the two of them was that if there was any threat or danger to either of them, they would use a physical signal to stop the intercourse.
"He said on the morning of question, she never gave him such signal to actually stop.
"This particular case being made is that this is entirely an accidental death in which there was no intention to kill or cause serious harm. This is without doubt an extremely tragic death."
A police sergeant objected to bail citing concerns over a risk of flight as Mietus has ties outside of Northern Ireland.
The court heard that the accused was in contact with a family member regarding a flight to Poland.
A prosecutor told the court that he asked a family member to print a ticket in his mother's name on Tuesday.
Sgt Brannigan said he had concerns about the seriousness of the alleged offence and the risk of interference with witnesses.
He told the court that relatives made statements that he told a relative on the morning of the alleged murder that he killed Ms Wyrebek.
He also said there are concerns that if he is released, he will be a danger to the community.
Mr Browne argued that the accused has "firm ties" to the community and has been working in Northern Ireland for a number of years.
He added that the defendant lives close to the border with the Republic and had "every opportunity to flee".
Mr Browne said: "The death occurred around half-past midnight and he was arrested the following afternoon. He was arrested in a very distressed state. He made comments to the effect, 'I killed her'.
"He was standing holding a knife when he was about to be arrested and was threatening self-harm such was the extent of his emotional distress."
However, the judge expressed "real concern" over the seriousness of the alleged offence and refused him bail.
The case will be heard on September 2.