A Turkish couple and their two minor children were found dead on Monday in their house in Esslingen, a town near southwestern Stuttgart city, in what authorities said was a case of suspected carbon monoxide poisoning.
Police spokesman Christian Woerne told Anadolu Agency that their initial investigation indicated that four members of the family died from accidental carbon monoxide exposure.
He said they had found no evidence so far indicating a crime or a suicide.
Turgay Ozturk, 29, his wife Filiz Ozturk, 29, and their 4-year-old son Mert and 3-year-old daughter Minel were found dead, after a relative called the police.
The poisonous gas has no smell or taste and its intake in large amounts may cause death.
