French police investigating the mysterious disappearance of a family of four have arrested two of their relatives, local media report.
The sister and brother-in-law of Pascal Troadec, one of the missing, have been detained in the city of Brest, where several items belonging to the family have been found.
There is still the possibility that some of them are alive, officials say.
An inquiry into murder, abduction and illegal confinement is under way.
The family lived in a suburb of Nantes, in western France. Pascal and Brigitte, both aged around 50, their son Sebastien, 21, and daughter Charlotte, 18 were last seen on 16 February.
The couple were arrested in Brest, some 300km (186 miles) from Nantes. They had already been questioned by police at the beginning of the investigation, AFP news agency reports, citing unnamed sources.
Prosecutor Pierre Sennes said on Friday that investigators did not exclude the possibility that some of the missing were still alive, French newspaper Le Figaro says.
On Thursday, police found Sebastien's car in Saint-Nazaire - the family's two other cars had been left parked in front of their house.
- Mystery of vanished French family
A day earlier, a social security card and a pair of trousers belonging to Charlotte had been found by a jogger in a forested area near Brest.
In a search of the family's house last week, investigators found bloodstains matching the DNA of the parents and Sebastien, but not of the daughter.
Traces of blood were found on Sebastien's phone, on Brigitte's watch and under the stairs, and it appeared that someone had tried to wipe them away, Mr Sennes said.Image copyright Reuters Image caption Police searched the two-storey house of the Troadec family last week
Authorities were informed of the family's disappearance by Brigitte's sister.
Investigators had initially focused on Sebastien, who had been sentenced to carry out community service after being convicted in 2013, when he was a minor, of making death threats on his blog.
Police had said in a bulletin on 24 February that he was suspected of "putting in place a macabre plan aimed at snuffing out the members of his family and maybe himself", AFP reports.
Reports on French media had suggested Sebastien had psychological problems while his dad had once suffered from depression.