The scaffolding firm that was renovating Notre-Dame in Paris when it burned says its workers smoked while they were on the job.
However, the construction company says there is no possibility a stray cigarette butt might have started the fire that destroyed the cathedral's oak-framed roof last week.
A spokesman for family-owned Le Bras Freres, confirming a report in French weekly Le Canard Enchaine, told Reuters that some workers of its Europe Echafaudage scaffolding unit had informed police that they had "sometimes" smoked on the scaffolding, despite a smoking ban on the site.
"We condemn it. But the fire started inside the building… so for company Le Bras this is not a hypothesis, it was not a cigarette butt that set Notre-Dame de Paris on fire," Le Bras Frères spokesman Marc Eskenazi said.
The Canard Enchaine reported that police had found the remains of seven cigarette butts in the burnt-out cathedral.
"This is not wrong," said a source close to the investigation, who declined all other comment.
Eskenazi said it was impossible to set a log on fire with a cigarette butt and questioned how cigarette butts could have been found on the site.
"If cigarette butts have survived the inferno, I do not know what material they were made of," he said.