Swiss police are investigating the death of a 22-year-old British woman found lifeless in the bathroom of a four-star hotel in the south of the country.
The body of Anna Florence Reed, 22, was discovered on Tuesday in Hotel La Palma au Lac in Muralto, in the district of Locarno.
Her 29-year-old German boyfriend, from Zurich, has been taken into custody and reportedly told police that the death was the result of a "sex game" that went wrong. He is facing a charge of pre-intentional homicide, the Telegraph UK reports.
Local media say a post-mortem examination has shown she died of suffocation or asphyxiation and that she had small cuts on her body, including on her neck.
The UK Foreign Office said it was offering assistance to the family.
The couple checked into the luxury 68-room four-star hotel on the weekend, according to a source.
They had paid a premium to secure Room 501 on the top floor and had been due to stay "several days".
But on Tuesday morning her lifeless body was found on the floor of the marble bathroom.
According to local reports the couple had argued so loudly in their room that the night porter intervened at 3am.
At around 6.30am, Ms Reed's boyfriend, who appeared "agitated", told the receptionist that his girlfriend "had a problem with her health".
A source said: "He said his girlfriend had a problem with her health, that she was ill."
"The receptionist could tell by his tone that it was serious, so he called an ambulance immediately.
"A few minutes later the ambulance was at the hotel. The medics went straight up to the room. She was on the floor of the bathroom.
"They tried to resuscitate her but there was no response. She was already dead."
The ambulance crew then alerted the police.
According to one local report, the couple were in a "solid" relationship and she had posted numerous photos on social media of their "idyllic" holiday on the Mediterranean in March.
Customers said there was nothing untoward about their behaviour.
Ms Reed's family is believed to be arriving in Switzerland today.