One of the co-owners of the Swiss bar where 40 people died in a fire on New Year's Eve has been detained.
Sources told Swiss media that Jacques Moretti, a French national, was a potential flight risk.
The blaze at Le Constellation bar in Crans-Montana left 116 people injured. Many of the victims were aged under 20.
It emerged this week that the bar in the ski resort had not undergone safety checks for five years.
Jacques Moretti and his French wife Jessica, who own the bar together, had been placed under criminal investigation by Swiss prosecutors.
They are both suspected of manslaughter by negligence, bodily harm by negligence and arson by negligence, the prosecutors' office in Valais said.
The prosecutors have stated that they believe the fire began when people celebrating the New Year raised champagne bottles with sparklers attached, igniting sound-insulating foam on the ceiling of the basement bar.
On Friday, Switzerland held a minute of silence during a national day of mourning for the victims of the fire.
Church bells rang across the country for five minutes in remembrance.
Operations at Zurich airport were briefly halted, and various public transportation services paused in solidarity.
In Crans-Montana, local firefighters received a standing ovation for their efforts during the emergency.
