The naked 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.
This therefore led to their suffocation.
According to officers, nobody had noticed the car engine had been left running for hours behind the metal gate of the garage.
Meanwhile, officers in the city had also started an investigation into the woman’s sudden disappearance
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.’