The Swiss bar that was the scene of a fire which killed 40 people and injured 116 had not undergone safety checks for five years, authorities have said.

The mayor of Crans-Montana, Nicolas Feraud, told a Tuesday news conference that he could not explain why Le Constellation bar had not been checked in so long, but that the council was "profoundly sorry". The venues should have been checked annually.

"We regret that - we owe it to the families, and we will accept the responsibility," he said.

He added that sparklers - which are believed to have caused the fire when they were raised too close to the ceiling - will be banned in local venues.

Local authorities will now bring in an external contractor to inspect and audit all 128 venues in the area.

Feraud conceded that a team of five people was inspecting more than 10,000 buildings in Crans-Montana and could not explain why the bar had not been inspected since 2019.

When asked repeatedly why the bar had not been checked in for so long, Feraud said, "I have no answer for you today."

"We're profoundly sorry about that, and I know how hard that will be for the families."

"I'm not resigning, no, and I don't want to," he later added.

Feraud said it would be "down to the judges" to decide whether members of the local authority would be included in a criminal investigation opened by Swiss prosecutors.

When the fire occurred on New Year's Day, the bar seemed to have many more people in it than legally permitted, which Feraud said was the managers of Le Constellation's responsibility to regulate.

Feraud said the maximum capacity was 200 people, with emergency exits designed to cater for 100 people on each side of its two levels. However, he did not know if the exit on the basement level was working.

Swiss prosecutors have placed the two bar managers under criminal investigation, which local media have named as a French couple, Jacques and Jessica Moretti.

They are both suspected of manslaughter by negligence, bodily harm by negligence and arson by negligence, the prosecutors' office in Valais said.

Prosecutors have said they believe the fire started when people celebrating the New Year raised champagne bottles with sparklers attached, setting light to sound-insulating foam on the ceiling of the basement bar.

Feraud said the use of soundproofing material on the bar's ceiling and the use of sparklers in the venue were extremely negligent.

Swiss national broadcaster RTS has shown footage from 2019 of partygoers holding bottles with sparklers. An employee warns them to be careful of the "mousse" - the French word for the acoustic foam panelling.

Questioned on the video, Feraud said it was likely no one in the council saw the images, and he wished it had been brought to his attention at the time, as he would have investigated.

Feraud said while inspections of the facility were conducted in 2016, 2018 and 2019, there were none from 2020 to 2025.

He told the press conference in 2015 that the owners renovated the bar and it did not require a permit, which was when the sound insulation foam was stuck on the ceiling.

"There were never any checks on this soundproofing foam. Our security agents did not consider it necessary," Feraud said.

Investigators will be assessing several elements, including the nature of the foam, compliance with standards for access and emergency exits in the basement.

Accounts from reported scenes include people pushing and shoving, notably on the staircase leading to the basement. Under Swiss regulations, doors are required to open in the direction of the exit and be clearly signposted.

Under Switzerland's political system, power is distributed among three levels of the confederation, 26 cantons and then about 2,131 municipalities.

While cantons set safety regulations, they need to be implemented by local authorities.

The Crans-Montana's failure to adhere to fire safety regulations by not inspecting Le Constellation from 2020 to 2025 may indicate a potential fault in the system.