Diego Fernandez de Cevallos, a prominent former Mexican presidential candidate, remains missing after being kidnapped in May, a government official told Reuters on Saturday, casting further doubt on reports of his release.
The newspaper El Universal said early on Saturday that Fernandez, a member of President Felipe Calderon's National Action Party, was freed on Friday night after his family paid a ransom of around $20 million.
"He has not been released," said the well-placed source, who asked not to be named and declined to comment further.
Another paper, Milenio, had said the report by El Universal was wrong, citing reliable sources but not giving any details.
El Universal had quoted a member of Fernandez's family as saying: "Everything is fine. He is OK and everything came out well."
Fernandez, a 69-year-old cigar-chomping lawyer, was abducted in central Mexico as he arrived at his ranch late at night. His car was found with some of his belongings inside and blood on a pair of scissors thrown on the ground nearby.
In the following months, his captors released photos of a blindfolded, bearded man who greatly resembled Fernandez in an apparent move to put pressure the politician's family to pay for his release.
Fernandez, known for his outspoken personality, is often called "Jefe Diego" (Boss Diego). He was a key figure in strengthening the National Action Party in the run-up to it winning the presidency in 2000 and ending seven decades of one-party rule by the Institutional Revolutionary Party.
Despite violence between drug cartels and security forces that has killed some 31,000 people in Mexico in the last four years, the identity of Fernandez's captors remains unclear.
Kidnapping of executives, public officials and ordinary citizens for ransom is rife, often ending in the deaths of victims.
Fernandez has close ties to key government figures such as Attorney General Arturo Chavez but does not currently hold any public office.