Florence Cassez became famous among her French compatriots as a frail and frightened-looking blonde convicted in a Mexico City court of participating with her Mexican boyfriend in an ugly kidnapping and sentenced to 60 years in prison.

On Thursday, after seven years of a relentless legal struggle from her prison cell against an often obscure and sometimes corrupt Mexican justice system, and backed by diplomatic pressure from the French government, Cassez flew home to France and a joyous national welcome.

On hand to greet her in the glare of television cameras were her family, friends and supporters who had agitated tenaciously for her release, as was French Foreign Minister Laurent Fabius, who declared that the government was “formidably happy” to see the 38-year-old freed from her Mexican ordeal.

“Hello, France. I am really happy to be here,” Cassez said after stepping out of the airplane. She said she had always held hope during her imprisonment but feared that she would be left to rot in her cell. “I have been declared innocent,” she added, taking the Mexican court decision a step further than it went.

The Mexican Supreme Court decided 3 to 2 on Wednesday that Cassez should be released after finding that her legal rights and Mexico’s procedural rules had been violated. The court found that the violations included a police-organized staging of Cassez’s 2005 arrest for TV cameras and multiple irregularities in evidence provided to the original judges.

“Justice has been rendered for this girl, who for seven years has been crying out her innocence, that her rights were violated, to say she wanted to recover her freedom,” one of her attorneys, Frank Berton, told reporters in Mexico City.

The ruling allowed Cassez to leave prison and board an overnight plane for Paris, but it did not settle the question of her guilt or innocence. “We will never know whether Florence is guilty or innocent, but we know for certain there are specific people who violated due process,” Luis Gonzalez Placencia, president of the Mexico City Human Rights Commission, told the Associated Press.

Cassez’s friend Israel Vallarta headed a gang called Zodiac, which Mexican police alleged was responsible for a dozen kidnappings. Cassez said Vallarta had told her that he sold cars for a living. Arrested and imprisoned at the same time as Cassez, Vallarta has not been tried, according to news reports from Mexico City.

Cassez’s case — she was sentenced to 96 years in 2008, reduced to 60 years on appeal a year later — had been a major irritant in French-Mexican relations. Her family and supporters, along with some French officials, complained that she was being made a scapegoat for the Mexican government’s inability to stop a wave of kidnappings that had become a troubling political issue for then-President Felipe Calderon.

Mexico canceled a planned year-long celebration of Mexican culture in French cities in 2011 after then-President Nicolas Sarkozy urged French officials organizing the observances to use them in a government campaign to lobby Calderon for Cassez’s release.

“I remember when Nicolas Sarkozy took up my cause,” Cassez recalled at an airport news conference. “He saved my life.”

Since Mexico’s election of President Enrique Peña Nieto, who took office last month, French officials have hoped that a new political climate would prompt the Supreme Court to review the evidence in Cassez’s case more favorably. Against that background, French President Francois Hollande saluted Wednesday’s ruling not only as a victory for justice in Mexico but also as a sign that French-Mexican relations were back on course.

“I want to recognize the Mexican justice system because it put the law first,” Hollande said in a television statement. “That was the trust we put in it. And today we can say that between France and Mexico, we have the best relations it is possible to have.”