PARIS • French presidential candidate Emmanuel Macron's team has blasted a "massive and coordinated hacking attack" against his campaign after a flood of internal documents were released online, barely 24 hours before the election today.
The centrist candidate's furious staff said the release late on Friday of thousands of e-mails, accounting documents and other files was an attempt at "democratic destabilisation, like that seen during the last presidential campaign in the United States".
The documents spread on social media just before midnight - when 39-year-old Mr Macron and his far-right rival Marine Le Pen officially wrapped up campaigning for today's decisive run-off vote - with his aides calling the leak "unprecedented in a French electoral campaign".
Mrs Hillary Clinton has alleged Russian hacking of her campaign's e-mails was partly to blame for her defeat in last year's US presidential election to Mr Donald Trump.
France's presidential election commission yesterday advised the media not to publish details of Mr Macron's campaign e-mails, warning that publication could lead to criminal charges and that some of the documents were probably fake.
But its rules may be difficult to enforce in an era where people get much of their news online, information flows freely across borders and many users are anonymous.
As much as 9GB of data was posted on a profile called EMLEAKS on the site Pastebin, which allows anonymous document sharing.
Mr Macron's team said the files were stolen weeks ago, when several officials from his En Marche! party had their personal and work e-mails hacked - one of "an intense and repeated" series of cyber attacks against Mr Macron since the launch of the campaign.
"Clearly, the documents arising from the hacking are all lawful and show the normal functioning of a presidential campaign," aides said in a statement.
But they warned that whoever was behind the leak had mixed fake documents with real ones "in order to sow doubt and disinformation".
The WikiLeaks website posted a link on Twitter to the trove of documents, saying it was not responsible for the leak but that it was examining parts of the cache.
Ms Le Pen's campaign staff said its website had also faced "regular and targeted" attacks, but it did not appear that her campaign documents had been compromised.
Last month, cyber security research group Trend Micro said Russian hacking group Pawn Storm had targeted Mr Macron's campaign, using phishing techniques to try to steal personal data.
Senior Le Pen aide Florian Philippot suggested on Twitter that the leak might contain information that the media had deliberately suppressed.
The leak came at the end of a frantic final day of campaigning and as fresh security concerns emerged following the arrest of a suspected extremist near a military airbase on Friday.
The arrest comes after the death of a policeman in a shooting attack last month in Paris' Champs Elysees, three days before the first election round. It was claimed by the Islamic State in Iraq and Syria (ISIS).
Guns, a pledge of allegiance to ISIS and several of the terrorist group's flags were found, said sources close to the case.
In the first round of the election, Ms Le Pen finished second behind Mr Macron, with the two candidates winning 21.3 per cent and 24.01 per cent of the vote respectively.
Polls released earlier on Friday showed Mr Macron gaining momentum. The polls forecast victory for the pro-European, pro-business former economy minister, with around 62 per cent of votes compared with 38 per cent for Ms Le Pen.
AGENCE FRANCE-PRESSE, REUTERS, NYTIMES