Here are the top 10 points in the big story:
Nicolas Sarkozy is being investigated for illicit campaign financing, misappropriation of Libyan public funds and passive corruption. He is already charged in two other cases -- one relating to a system of fake invoices devised to mask overspending on his failed 2012 election campaign, the other for alleged influence peddling involving a judge.
Judges decided they had enough evidence to charge the combative one-term president in the Gaddafi cash case Wednesday after five years of investigation and two days of questioning in police custody in the Paris suburb of Nanterre.
The first claims of Gaddafi interference were made by the Libyan dictator's son Seif al-Islam in 2011 who said that Nicolas Sarkozy should "give back the money he took from Libya to finance his electoral campaign." The revelations came as Sarkozy was trying to win re-election, but he ultimately lost the 2012 race to Socialist Francois Hollande.
A year later, an investigative French news website Mediapart published a document allegedly signed by a Libyan intelligence chief saying that Gaddafi had agreed to support Nicolas Sarkozy with up to 50 million euros. Mr Sarkozy has sued the website.
Also, former Libyan spy boss Abdullah al-Senussi, a lawyer to a former prime minister, one of Gaddafi's cousins and a former interpreter have all made allegations about illicit financing.
Mr Sarkozy lashed out at Franco-Lebanese businessman Ziad Takieddine, who claims to have delivered three cash-stuffed suitcases from Kadhafi in 2006 and 2007, when he was preparing his first run for president. Takieddine, who claimed he provided 1.5 to 2 million euros, has "highly suspect characteristics and a questionable past", Mr Sarkozy said.
The 63-year-old right-winger has in the past called the allegations "grotesque" and a "manipulation". Figaro newspaper quoted Mr Sarkozy that he was in "living hell" since the allegations emerged in 2011.
Mr Sarkozy demanded he be treated as a witness rather than a suspect in the Gaddafi cash case and urged magistrates to consider "the violence of the injustice" if it was proven, as he claims, that the accusations are a "manipulation by the dictator Gaddafi or his gang". "In the 24 hours of my detention I have tried with all my might to show that the serious corroborating evidence required to charge someone did not exist," he said.
Nicolas Sarkozy was first taken into custody in the Nanterre suburb west of Paris on Tuesday morning before returning for another round of questioning on Wednesday morning. "I stand accused without any tangible evidence through comments made by Mr Gaddafi, his son, his nephew, his cousin, his spokesman, his former prime minister," he said.
Mr Sarkozy has stepped back from frontline politics since his failed re-election bid, but he still holds considerable influence with his rightwing Republicans party. The party has so far backed him publicly. "Being charged does not necessarily mean you are guilty," said Republicans leader Laurent Wauquiez.