A Frenchwoman jailed in Mexico in 2007 for 60 years for kidnapping has been freed, after the Supreme Court ruled her rights were violated.
Florence Cassez had denied the charges and many irregularities were found in the case, including a staged televised police raid.
Three judges on a panel of five voted to have Ms Cassez released immediately.
The case provoked tensions between Mexico and France, where news of her release was widely welcomed.
Ms Cassez, 38, was driven to Mexico City's international airport and landed in Paris on Thursday after an overnight Air France flight.
"I have suffered as a victim for the last seven years," she told reporters at Charles de Gaulle airport, where she was met by family, members of her support group and dignitaries including French Foreign Minister Laurent Fabius.
"This is also a great victory for Mexicans in the sense that justice has been done," she said.
Mr Fabius said the decision to free her showed that Mexico was a "great democracy".
Ms Cassez's mother, Charlotte, told French television earlier the case had been full of suspense right to the end. "It's an explosion of joy. I can't quite believe it," she said.
In a statement, President Francois Hollande said the decision marked the end of a "particularly painful period".
"France thanks all those who, in Mexico as well as here at home, have fought so that truth and justice prevail," he said.
Mr Hollande spoke to Ms Cassez by phone on Wednesday evening. Details of the conversation have not been revealed.
"This is a historic day for Mexican justice," said her lawyer Frank Berton.
Florence Cassez was arrested on 8 December 2005 at a ranch near Mexico City where several hostages were found.
She denied knowledge of the kidnappings, carried out by a gang - the Zodiacs - led by her Mexican then-boyfriend Israel Vallarta, who confessed.
The next day, Mexican TV showed what it described as live footage of a police raid, which it later transpired had been a reconstruction performed at the request of the media.
The Supreme Court judges ruled that the reconstruction had violated Ms Cassez's rights.
The decision to release her has been sharply criticised by one of the hostages, Ezequiel Elizalde, BBC Mexico correspondent Will Grant says.
Mr Elizalde testified against Ms Cassez and has condemned the Supreme Court's decision as "disgusting", describing Mexico's institutions as "filth".
This was the second time that the Supreme Court had taken a vote on freeing Ms Cassez.
Last March, however, the judges decided against her release, despite acknowledging serious irregularities in the process.
When first convicted, she was jailed for 96 years, But, in 2009, a court of appeal reduced the term to 60 years.
French authorities tried to extradite her, but the move was blocked by the Mexican government.
Mr Hollande's predecessor in the Elysee Palace, Nicolas Sarkozy, championed the case and repeatedly clashed with the Mexican government of then-President Felipe Calderon.
Diplomatic tensions reached a peak two years ago when Mexican authorities cancelled a high-profile cultural event in Paris.