On Thursday, speaking on France 2 TV, Fillon accused Hollande of revealing important investigation documents, stressing, as quoted by Le Parisien, that "a head of state has never gone so far in illegality."
Hollande condemned Fillon’s accusations, saying that they are false.
"Mr. Fillon's remarks, which add to the revelations of recent weeks, have no basis and cause an unbearable turmoil in the presidential campaign," the Elysee palace said in a statement, as quoted by Le Parisien on Thursday.
Speaking on France 2 TV on Thursday, Fillon also dismissed all accusations against him alleging that he was paid $50,000 for organizing a meeting with Russian President Vladimir Putin. Fillon called the allegations, first revealed by the French Canard Enchaine weekly on Wednesday, a "shameless lie."
Kremlin spokesman Dmitry Peskov dismissed the reports on Wednesday, saying they were "fake news."
The French presidential election is scheduled for April 23, while the run-off is set for May 7.