Prosecutors investigating the cause of the mammoth blaze that tore through the iconic Notre Dame Cathedral in April have ruled out any criminal intent.
Paris authorities believe an electrical fault or a burning cigarette is likely to blame for the catastrophic fire that severely damaged the 850-year-old world heritage-listed site.
Yet it was not yet possible to conclude what was the most likely theory.
In a statement on Thursday (Australian time), Paris prosecutor Remy Heitz said they were examining many hypotheses “including a malfunctioning of the electrical system or a fire which started with a badly stubbed-out cigarette”.
So far, after interviews with some 100 witnesses, there is no evidence to support any theory of “a criminal origin” to the fire, the statement read.
The blaze ripped through the medieval cathedral on April 15, destroying the roof, toppling the spire, and almost bringing down the main bell towers and outer walls before firefighters brought it under control.
Mr Heitz said the investigation had still not determined the actual cause of the fire.
“If certain failings, which may explain the scale of the fire, have been brought to light, the investigations carried out to this date have not yet been able to determine the causes of the fire,” Mr Heitz said.
“Deeper investigations, using significant expertise, will now be undertaken.”
In April, a spokesman for scaffolding company Le Bras Freres which had been involved in mending the roof and spire of Notre-Dame before it went up in flames, admitted that workers flouted smoking bans.
“We regret it,” the spokesman said at the time, adding: “In no way could a cigarette butt be the cause of the fire at Notre-Dame.”
President Emmanuel Macron has set a target of five years for restoring Notre-Dame, which dates back to the 12th century and is one of Europe’s most iconic landmarks.
Hundreds of millions of dollars have been pledged as part of the effort to rebuild the fire-ravaged Cathedral, with the world’s third-richest man and Louis Vuitton chief executive Bernard Arnault promising €200 million euros ($316 million) mere days after the building went up in flames.