Florence Cassez after being freed from prison

A French national has been freed after after a Mexican court overturned her 60-year sentence for belonging to a kidnapping gang, due to failings such as the police staging a fake arrest for the media.

Supreme Court judges voted to free 38-year-old Florence Cassez, who has been held in a Mexican prison since her arrested in 2005 for aiding a kidnapping ring called the Zodiacs, run by her Mexican boyfriend, reported the Associated Press.

The judges quashed the verdict due to a series of procedural irregularites and violations of Cassez's rights, including police forcing her to take part in a staged recreation of her arrest for the media, which included images of supposed kidnap victims being freed, and holding her without consular assistance. However, the court did not rule on whether she was guilty of the charges.

In France, Cassez's friends and family, along with the media and politicians, have long campaigned for her release, and the case had become a source of diplomatic tension between France and Mexico. In contrast, in Mexico, the ruling was greeted with dismay by people who had been kidnapped by the group, and relatives of victims.

Cassez admited she had lived in the ranch outside Mexico City where the gang held their victims, but denied any role in the kidnapping.

The original trial included the testimony of three victims of the gang, one of whom claimed Cassez had threatened to cut off his finger, France24 reported. However, the judge who paved the way for her relase by ordering a review of the case in May declared that some of the testimony should be discounted as it was contradictory, and possibly influenced by the police's staged recreation.

Insight Crime Analysis

Cassez's case demonstrates the failures of Mexico's historically corrupt justice system, which saw a 90 percent impunity rate for all crimes under the government of Felipe Calderon, according to the United Nations.

Cases often flounder due to irregular arrests and investigations, or corruption. In a high-profile case last year, the former mayor of Tijuana, Jorge Hank Rhon, was freed after it was revealed the army had manipulated evidence against him.

However, Cassez's release may reinforce the sense that crimes such as kidnapping are not punished in Mexico, which has one of the worst kidnapping rates in the world -- an average of 72 a day in 2012, according to non-governmental organization the Council for Law and Human Rights (Consejo para la Ley y los Derechos Humanos - CLDH).