French presidential candidate Emmanuel Macron's campaign said it has been the victim of a massive and coordinated hacking operation, reports CNBC.
The campaign said fake documents, mixed with authentic ones, were released together, in an attempt to sow doubt and misinformation before voters go to the polls to choose the country's next president in a run-off with Marine Le Pen.
Sunday's election is seen as the most important in France for decades, with two diametrically opposed views of Europe and France's place in the world at stake.
The National Front's Le Pen would close borders and quit the euro currency, while independent Macron, who has never held elected office, wants closer European cooperation and an open economy.
The candidates of France's two mainstream parties, which have alternated in power for decades, were both eliminated in the first round of voting on April 23.
Earlier, a large trove of emails purporting to be from Macron's campaign was posted online late Friday. Some nine gigabytes of data were posted by a user called EMLEAKS to Pastebin, a document-sharing site that allows anonymous posting.
Macron's campaign said, however, that it is not concerned about the leaked documents as they show routine operations of a presidential campaign.