The luxury Swiss Alps nightclub where at least 40 people were killed and nearly 120 others were injured in a New Year’s Eve inferno, had previously released a promotional video advertising flaming champagne bottles, which authorities deemed the cause of the tragedy.
Le Constellation, a bar in the resort town of Crans-Montana, Switzerland, posted the video on YouTube showing waitresses in helmets moving through the dark, crowded club carrying bottles topped with sparkling candles.
In no arrests have been confirmed.
Pilloud said investigators will work to determine if anyone bears criminal liability for fire by negligence, homicide by negligence, or injuries by negligence.
Since the tragedy, hundreds of people have gathered outside the burned-out venue in Crans-Montana, laying flowers and candles as families waited for news of missing loved ones.
Italian authorities said the death toll could be as high as 47, the disaster as "one of the worst tragedies our country has ever known," noting that many of the victims were young people celebrating the New Year.
While the majority of those hurt were Swiss, four Serbians were injured, along with others from Bosnia, Belgium and Portugal.
Italy and France confirmed some of their nationals remain missing.
Le Constellation did not immediately respond to Fox News Digital's request for comment.
Fox News Digital's Michael Dorgan contributed to this report.