The distraught owners of the Swiss nightclub where at least 40 revelers were killed in a raging New Year’s Eve fire insisted their venue followed every safety regulation before the unthinkable tragedy.

Jacques and Jessica Moretti spoke out for the first time since the deadly blaze tore through Le Constellation nightclub after sparklers attached to champagne bottles ignited the ceiling during the boozy bash.

“Everything was done according to the regulations,” Jacques, 49, told Swiss outlet La Tribune de Genève.

The couple, who were interviewed by police Friday, vowed to work and cooperate with authorities amid the investigation into the fiery nightmare.

“We will do everything in our power to help clarify the causes,” the shaken husband told the outlet.

“We are doing everything in our power. Our lawyers are involved.”

The French couple bought the club in 2015, transforming a once-rundown cafe into a nightlife hotspot in the popular ski destination, according to Swiss media.

While Jacques was at a nearby property when the blaze erupted after midnight, his 40-year-old wife was reportedly inside the jam-packed club and suffered burns to her arm in the horror.

The flames spread quickly through the bar, which could hold up to 300 people, making it difficult to breathe around 1:30 a.m. Thursday morning.

The initial fire then triggered what firefighters refer to as a “flashover,” in which all the combustible material in a room ignites at once, causing multiple explosions, Swiss authorities said.

A haunting new photo captured the moment the fire erupted, showing flames spreading over the low ceiling as unsuspecting partygoers waved their sparklers and bottles high in the air.

“It was firework candles inside a champagne bottle that caused the explosion. The entire ceiling of the bar caught fire,” one witness, who gave her name as Victoria, told French broadcaster BFMTV.

Another image captured a woman in a crash helmet holding up lit bottles while being carried back on the shoulders of a masked man.

The sparkers appeared to be a popular party gimmick of Le Constellation.

Promotional videos from last year showed waitresses weaving through the crowd with flaming champagne bottles held aloft and nearly brushing against the ceiling.

“Several people have been interviewed and observations have been made on the premises,” Swiss prosecutor Beatrice Pilloud told reporters Friday, noting the investigation will determine if the owners bear any “criminal liability,” according to the US Sun.

“We will also focus on the number of people who were present at the party, the number of people that the bar is authorized to host, the exit routes and the access routes into the premises.”