Diego Fernandez de Cevallos, a former Senator, presidential candidate, and longtime political 'Jefe' of the National Action Party (PAN) was freed on Monday, but the mystery of who took him captive for over seven months remains.
Cevallos spoke to reporters on Monday, with strong words for the government and in apparent good health.
"The authorities have some work to do," he said.
He gave no indication of who his captors were but promised more information in the near future.
Fernandez de Cevallos was reportedly taken by four armed men on May 14, when he arrived at his ranch house in the Queretero province. There was some blood on his car, the only indication of a struggle.
But the government's efforts to track his captors failed, so the family publicly requested the PAN-government of Felipe Calderon to take a step back and negotiate themselves. It is not known if they paid a ransom, and little is known of the group that took him captive.
A group calling itself the Network for Global Transformation took responsibility for the kidnapping, and sent various statements to the press during his captivity, criticizing Fernandez de Cevallos for being part of the "hardline, fundamentalist right-wing."
Mexico's only rebel group, the Popular Revolutionary Army (EPR), denied it had any involvement in the kidnapping.
Shortly, after his kidnapping, Calderon blamed "organized crime."