Swiss bar owner Jacques Moretti was questioned by lawyers acting for victims' families on Wednesday, over the New Year's Day fire disaster in Crans-Montana that left 41 people dead and 115 injured.

He arrived for the hearing in Sion with his wife, Jessica, whose lawyer Yaël Hayat described the latest hearings as moments of truth. Jessica Moretti faces questions on Thursday.

Ahead of the hearing, one mother told Swiss TV she needed to know what had gone wrong and why.

What's important is that the whole truth comes out, said Laetitia Brodard-Sitre, whose 16-year-old son Arthur died in the fire.

There must be no more lies, she told public broadcaster SRF. I want everyone to take responsibility; politics and parties don't matter to me.

Jacques and Jessica Moretti are under criminal investigation for involuntary manslaughter, as well as bodily harm and arson through negligence. Neither is being held in custody; Mr Moretti was released on bail last month.

The couple have been criticized by several former employees for safety failings which have emerged since the fire. Sparkling candles in champagne bottles have been blamed for setting light to the ceiling, and footage has emerged showing an employee using snooker cues to push sound-proofing foam back into place on the ceiling weeks before the disaster.

No fire inspection had taken place there since 2019, and the former security officer at Crans-Montana's town hall told a hearing that local authorities had not closed any establishment there because of fire risks until last month.

The inquiry continues as many victims' families seek clarity and accountability amidst lingering grief and pain from the tragedy.