A key witness whose statements helped convict French national Florence Cassez on charges she led a kidnapping ring, later retracted the testimony, which he said had been obtained "by means of torture," court documents showed Thursday.

David Orozco, who was arrested for his alleged role in the same kidnapping ring in May 2009, fingered Cassez and her boyfriend, Mexican national Israel Vallarta as the leaders of the operation.

Largely because of Orozco's testimony, Cassez was sentenced to a 60-year prison term. But court records obtained by AFP showed that Orozco in July 2009 told a judge that the statement against Cassez had been obtained "by means of torture."

The document signed by Judge Eduardo Javier Saenz Hernandez showed that Orozco told the judge he never met Cassez or Vallarta, and denied belonging to the gang of kidnappers -- contrary to his public pronouncements, which were widely broadcast on Mexican television.

"I didn't do it, I don't know those people," read Orozco's statement to the judge, according to the documents.

Cassez, who insists she is innocent, was convicted of the crime and is currently serving a 60-year prison sentence in Mexico

Orozco, who said he also is innocent of the kidnapping charges, claims he is an honest businessman who was kidnapped by masked gunmen who turned out to be police officers.

He said he was beaten and electrocuted, and said the gunmen threatened to kidnap his wife and son before making him issue the televised statement.

"They started to tell me what they wanted me to say, and gave me the names of Israel Vallarta and the French woman," according to his testimony as it appears in court documents.

Cassez, who is in her mid-30s, was arrested in December 2005 at a home where several kidnap victims were found. She was later convicted of participating in kidnappings with Vallarta, who admitted taking part in the crimes, but claims Cassez is innocent.

French President Nicolas Sarkozy is pressing for Cassez to return to France to serve out her sentence near her parents, but Mexican President Felipe Calderon has rejected the possibility of her repatriation.