International Monetary Fund chief Christine Lagarde has said the decision to formally investigate her over negligence claims was "without basis".
In a statement after a fourth round of questioning before magistrates, Lagarde said she was returning to work in Washington later in the day.
"After three years of proceedings, dozens of hours of questioning, the court found from the evidence that I committed no offence, and the only allegation is that I was not sufficiently vigilant," Lagarde said.
International Monetary Fund chief Christine Lagarde has been placed under formal investigation for negligence relating to a long-running political fraud case, an unnamed source has told Reuters.
Lagarde will appeal the French magistrates' decision to place her under formal investigation, saying the allegation of negligence was unfounded, the source stated.
The inquiry into French businessman Bernard Tapie has embroiled several of former president Nicolas Sarkozy's cabinet members, including Lagarde, who was finance minister.
Tapie was awarded €403 million (£321 million) in a 2008 arbitration payment under Sarkozy's presidency to settle a dispute with the now-defunct state-owned bank Credit Lyonnais over a share sale in 1993.
The boss of the International Monetary Fund has issued a new warning about the dangers of rising houses prices in Britain.
Christine Lagarde said the Bank of England should rein in risky mortgages.
ITV News Economics Editor Richard Edgar reports.
The head of the IMF, Christine Lagarde, has firmly denied suggestions that she may become the next president of the European Commission.
Speaking at an IMF press conference in London, Ms Lagarde insisted: "I'm not a candidate and the reason I'm not a candidate is I have a job and it's a job I happen to think is rather important at the moment."
She also made a reference to the 70th anniversary of the D-Day landings, saying: "When you start something you've got to finish the job, that's what a few people did 70 years ago, thank goodness."
The Chief Secretary to the Treasury says today's IMF report on the British economy is "extremely good news" and a "strong endorsement" of the Government's strategy.
However, Danny Alexander acknowledged that ministers have to "keep a close eye" on the housing market to defuse any risks.
The head of the IMF has given a ringing endorsement of the UK's recent economic progress, saying the news has been "pretty much all good".
At the same time, Christine Lagarde warned of "risks looming on the horizon" from weak productivity and an overheating housing market.
The head of the IMF has suggested the Bank of England should increase interest rates, as keeping them at their low 0.5% rate could "increase risks to financial stability".
Christine Lagarde said the IMF view was that having low interest rates "could further fuel house prices" and therefore risk destabilising the economy.
She said it was up to the Bank of England to take action on rates "in a gradual fashion as the first line of defence against risks to financial stability arising from the housing market".
The head of the IMF has called for the Government to put in place more measures to boost housebuilding.
Speaking at the Treasury this morning as the IMF gives its yearly assessment of the British economy, Christine Lagarde said:
"Addressing imbalances in the housing market...will require further measures to increase the availability of land for development and to remove unnecessary constraints to land use.
The head of the IMF, Christine Lagarde, has dismissed suggestions that she is in line for a new role as President of the European Commission, the EU's executive body.
ITV News Economics Editor Richard Edgar is at a press conference with Ms Lagarde at the Treasury.
The head of the International Monetary Fund has welcomed the UK's economic progress over the last year but warned of major risks that remain.
Delivering the IMF's annual report on the state of the British economy, Christine Lagarde said that "the news coming out of the UK has been pretty much all good".
She pointed to the UK's growth rate being the highest of the advanced economies, along with signs that the economy is "rebalancing" towards a more investment-driven economy.
However, she also identified two major risks to Britain's prosperity - weak productivity and the the rapid rise of house prices.
"There is no room for complacency as there are risks looming on the horizon," Ms Lagarde said.