A large trove of emails from the campaign of French presidential candidate Emmanuel Macron was posted online late on Friday, a little more than a day before voters go to the polls to choose the country's next president in a run-off against far-right rival Marine Le Pen.
Some nine gigabytes of data were posted by a user called EMLEAKS to Pastebin, a document-sharing site that allows anonymous posting. It was not immediately clear who was responsible for posting the data or whether the emails were genuine.
In a statement, Macron's political movement En Marche! (Onwards!) confirmed that it had been hacked.
"The En Marche! Movement has been the victim of a massive and co-ordinated hack this evening which has given rise to the diffusion on social media of various internal information," the statement said.