A judge in Switzerland has ordered that one of the two co-owners of the ski resort bar where 40 people died in a fire on New Year's Eve be kept in detention for 90 days.

Swiss prosecutors have argued that Jacques Moretti, a French national, is a potential flight risk. He and his wife Jessica, who is also French, are suspected of manslaughter by negligence, bodily harm by negligence, and arson by negligence.

The blaze at Le Constellation bar in Crans-Montana also left 116 people injured, with many victims aged under 20.

The fire is believed to have been started by sparklers in champagne bottles raised too close to the ceiling during celebrations. Authorities acknowledged last week that the bar had not undergone safety checks for five years.

Jacques Moretti was first detained on Friday for an initial period of 48 hours. On Monday, a judge at what is known as a court of coercive measures ruled that he should be kept in custody for three months—a period that can be renewed under Swiss law. The couple was placed under criminal investigation days after the devastating fire.

Moretti's wife, Jessica, who is under house arrest, expressed her sorrow about the unthinkable tragedy. Reports suggest the fire started when people celebrating the New Year raised champagne bottles with sparklers attached, igniting sound-insulating foam on the ceiling of the basement bar.

Families of the victims are devastated to learn that the bar had not been inspected for five years. Such venues should receive annual checks, and Crans-Montana Mayor Nicolas Feraud expressed regret over this oversight, promising to ban sparklers in local venues. Most of the fire's victims were young, with eight under the age of 16, and many injured remain hospitalized with severe burns.