Macron, a liberal centrist, is pro-business and a strong supporter of the European Union, EU, while Le Pen campaigned on a France-first, anti-immigration programme.
In a statement released after a morning meeting, the watchdog said the leaked data had been "fraudulently" obtained and that fake news has probably been mingled with it.
Projected results in the ongoing French presidential election have it that two of the major contenders, Emmanuel Macron and Marine Le Pen are through to the runoff election coming up in May.