The French authorities are not exactly slow to spot a terror attack but they have said there is no evidence that the Notre Dame fire was caused by one. That hasn’t stopped the far right from hatching conspiracy theories. They just can’t help themselves.

“More and more people agree with me,” claimed the ageing gent on the banks of the Seine on Tuesday afternoon. He was part of the crowd looking at the damage done to Notre Dame Cathedral in the previous night’s fire.

Having blamed immigrants for the lack of affordable housing, he went on to express scepticism about the “theory” that the fire had started by accident.

Indeed, he is not alone.

Officials and experts say there is no evidence of arson or a terror attack. The conflagration is most likely to have been set off by an accident, possibly connected to restoration work being carried out in the cathedral, they say. But that hasn’t stopped the conspiracy theorists soaping the ropes for a prospective pogrom.

With sickening predictability, far-right websites, known as the “fachosphere” in France, launched a desperate search for evidence that the disaster was the result of an Islamist terror attack.

Here are some of their claims:

• The two fires theory: A tweet by Pierre Sautarel of fachosphere favourite Fdesouche.com claimed there were two fires and therefore that they must have been started deliberately. As evidence, it cited well-known newsreader David Pujadas, who in a live broadcast did point out that there were two  lots of flames, but without implying  they had been started separately. That did not prevent other far-right fantasists, in France and abroad, from spreading the rumour.
• The mysterious imam/Yellow Vest: A Spanish tweet claimed that a figure filmed walking along the side of the cathedral was there when the building was supposed to have been empty and must have been an imam or, failing that, a Gilet Jaune. As Libération newspaper established, the report was broadcast live on Spanish TV after emergency services had arrived and the figure was wearing a high-visibility jacket and safety helmet because, well, you would in those circumstances, wouldn’t you?
• Well, look, it just must have been terrorists: All France’s main parties, even the party previously known as the Front National (FN), have abstained from claiming the disaster was a terror attack. Not the Islamophobes posing as secularism-defenders at Ripostelaïque, however. They declared that “inevitably, we’re all thinking it might be an attack on France and all that she stands for … And if it’s an attack it can only be a Muslim attack.” Philippe Karsenty, a right-wing councillor from the posh Paris suburb of Neuilly, won the distinction of being fact-checked by Fox News when he told an interviewer that the “politically correct will tell you it was an accident”. Perennial presidential candidate Nicolas Dupont-Aignon, an anti-tax obsessive who backed the FN’s Marine Le Pen in the 2016 second round, demanded an official inquiry “to know if it was a terror attack or not”. And vehemently pro-Israel MP Meyer Habib managed to combine both the above items of fake news in one tweet that asked “Accident or criminal attack?”, following it with another that indignantly denounced government ministers who have condemned conspiracy theories.

In today’s digital world fake news spreads before the truth has the time to put its boots on, so inevitably these and other unfounded rumours found their way to dodgy sites from Australia to America. In the US Alex Jones’s Infowars gave a headline to a tweet that was soon deleted by its author, who told BuzzFeed News “I never should have tweeted it.”

The hate-mongers have had a little help, however. Two members of the national committee of the left-wing students’ union Unef gave them just what they wanted when they sneered at “some cathedral woodwork burning”, people “crying over some bits of wood”,  one declaring that she “couldn’t care less about the history of France” and that the outpouring of emotion was white people’s ravings.

Conspiracy theories also put in a brief appearance on the Gilet Jaunes’ social networks. Some contributors judged it suspicious that the fire led to the cancellation of the president’s address to the nation on prime-time TV. Macron was due to outline his response to the national debate he organised in the wake of the high-vis protests.

It’s difficult to imagine the president declaring “Shit! I haven’t finished my speech. Somebody set fire to Notre Dame!” and, knowing what we do about the man, we can be fairly sure he was convinced of the brilliance of his proposals. Gilet Jaune moderators seem to have shut down those debates, in any case. And Macron’s main proposals have been leaked. Surprise, surprise, he leads with tax cuts, which the prime minister has already explained will mean more cuts in services. Not really worth setting a national monument on fire for.

To listen to me talking to KPFA radio’s Kris Welch about the Notre Dame fire (including the strange story of the kings’ entrails), click here