A naked couple was found dead in a car and it is believed they suffocated after turning on the engine to keep warm while having sex.
The bodies of a 39-year-old man and a 44-year-old woman were discovered by police in a locked garage in the city of Bottrop in western Germany's North Rhine-Westphalia state.
The names of the couple have not been released but investigators say it appears they turned on the car engine to get warm, leading to their suffocation.
The man had been reported missing by his family after he had not been seen for days. This led to a search. Meanwhile, officers in the city had also started an investigation into the woman's sudden disappearance. Police later opened the garage door to find the couple dead. Nobody had noticed the car engine had been left running for hours behind the metal gate of the garage which is located behind a commercial building.
Police said there appeared to be no evidence of a crime but forensic scientists were working hard to establish exactly what happened. Tests are being carried out to ascertain CO levels in the blood of the couple.
A police spokesman said: "At the moment all evidence points to an accident. To put all doubts to rest, the public prosecutor ordered an autopsy be performed on the bodies."