Macron's French presidential campaign emails leaked online

Emmanuel Macron, head of the political movement En Marche !, or Onwards !, and candidate for the 2017 presidential election, is pictured through a window of his hotel during a campaign visit in Rodez, France, May 5, 2017. REUTERS/Regis Duvignau

FRANKFURT/PARIS (Reuters) - Leading French presidential candidate Emmanuel Macron's campaign said on Friday it had been the target of a "massive" computer hack that dumped its campaign emails online 1-1/2 days before voters choose between the centrist and his far-right rival, Marine Le Pen.

Macron, who is seen as the frontrunner in an election billed as the most important in France in decades, extended his lead over Le Pen in polls on Friday.