The "Hollande affair" has taken an unexpectedly sinister turn with claims - and counter-claims - that the flat used for the president's alleged love tryst with an actress was linked to the Corsican mafia.
French media reported that the apartment where Francois Hollande met Julie Gayet was lent to her by a friend who was involved with two mobsters.
However, the friend, Emmanuelle Hauck, denied her ex-husband Michel Ferracci, who was given an 18-month suspended sentence in connection with money-laundering last November, had ever owned, rented or lived in the property and threatened to sue for defamation.
It was later revealed that after splitting from Ferracci, Hauck lived with Francois Masini, who was shot dead last May in an apparent gangland killing.
As the opposition lambasted Socialist Hollande for exposing the country to international ridicule, his official partner Valerie Trierweiler remained in hospital over what one official described as "a severe case of the blues".
Meanwhile, Hollande was preparing for a key press conference today in which he was expected to announce new goals and a timetable for reforms in front of 600 French and foreign journalists. Jean-Francois Cope, president of the Union for a Popular Movement party, described the scandal as "disastrous for the image of the presidential role" while declaring his commitment to France's privacy laws.
French newspaper Le Parisien reported that Trierweiler, 48, is ready to forgive Hollande, and claimed that Hollande told his partner that Closer was making his alleged affair public just a few hours before the magazine hit the newsstands.
Frederic Gerschel, a journalist at Le Parisien who was reportedly in contact with Trierweiler, claimed that Hollande did not spare his girlfriend the details.
"He denied nothing, not the escapades on scooter with his bodyguard in the middle of the night, nor the frequency of the secret meetings, or the date when this 'love affair' as the foreign press has baptised it, started several months previously," Gerschel wrote.
One of Trierweiler's friends told the paper: "The news hit Valerie like a TGV hitting the buffers. She was completely stunned. Of course she had heard the rumours going around Paris for weeks, but she wanted to believe they were false. To her, they [Trierweiler and Hollande] are still a couple."
Trierweiler was taken to hospital on Friday after Closer magazine published seven pages of pictures of Hollande visiting the apartment in Paris's chic 8th arrondissement and apparently staying overnight.
The magazine showed photographs of a man in a black helmet, alleged to be Hollande, being accompanied to and from the apartment by a bodyguard on a scooter on the last two days of December.
The new year could hardly have started worse for the French leader, who failed to keep a promise to the nation to halt the rise in unemployment by the end of last year and is now dealing with media allegations of a secret love affair.
Yet with polls showing most French are not unduly bothered by Hollande's private life, the real question is whether he will use the media event to show he is ready to tackle the double burden on the French economy - rising taxes and public spending.
"As is often the case, there are good intentions. But we will judge the deeds," said analyst Bruno Cavalier at Paris-based Oddo Securities.
Socialist Hollande, who in his 2012 election campaign labelled the world of finance his "enemy", ignited speculation of a U-turn with a New Year's address to the nation offering business leaders a "responsibility pact", trading lower taxes and less red tape for company commitments to hire more staff.
Striking a new tone, he also declared it was time to stamp out abuses of the country's generous welfare state and cut public spending.
Additional reporting by Reuters