Pascal Troadec, 49, his wife Brigitte, and their two children Sébastien, 21, and Charlotte, 18, have been missing since February 16. All of their mobile phones are off and there has been no activity on their bank accounts, according to Sennès.
The public prosecutor confirmed on Sunday that investigators had found blood stains underneath the stairs in the Troadec’s house in their hometown of Orvault, near Nantes in western France.
He added it seemed as if someone “had tried to wipe the blood stains away”.
Blood was also found on a mobile phone and ear buds, as well as a pair of shoes.
Preliminary laboratory results have confirmed that the blood found on the scene matches that of the Troadec family, according to Sennès.
Sennès described the strange discoveries investigators made while examining the premises on Thursday.
In the bathrooms, no toothbrushes or hair brushes were found. In the bedrooms, the beds were bare with no sheets. However, partly humid sheets were found hanging to dry on a clothesline inside. And wet clothes were still in the washing machine.
“It’s as if everyone just got up and left,” said Sennès.
However the family’s two cars are still parked in front of the house.
Police investigating possible mental health issues
Pascal has been described by a source in the case as having “problems with depression”, while others have described his son Sébastien as “odd”.
French daily Le Monde has reported that in 2013 Sebastien posted the following on a video game message board online: “What do I hate the most? My reflection.” And: “What makes me sad? My life.”
In one of his Twitter posts, he wrote: “If one really knew what was going on in my head, one would think I was a crazy person with no morals.”
Police were first informed of the family’s disappearance by Brigitte’s sister, who called authorities after not hearing from her sister in days.
Police have opened an investigation for first-degree murder, kidnapping and illegal confinement.