[Updated 6:41 p.m.] The case has rocked Mexico, with President Felipe Calderon saying he is closely monitoring the investigation into the disappearance of the former official, Diego Fernandez de Cevallos Ramos.
A statement on the Mexican president's website said that Calderon "from the first hours of the morning, has been in constant communication with the attorney general and with the secretaries of Interior and Public Security," about the investigation.
The statement said that Calderon has "communicated with one of the two children of Fernandez de Cevallos, who is facing this difficult situation with integrity, to offer his solidarity and the necessary backing to successfully locate Fernandez de Cevallos."
[Posted 5:12 p.m.] A former Mexican senator was reported missing on Saturday, Mexico's attorney general's office said.
The former official, Diego Fernandez de Cevallos Ramos, was last seen on the ranch of his home in Pedro Escobedo, in central Mexico's state of Queretaro, the country's official Notimex news agency reported.
The attorney general's office said that Fernandez de Cevallos' vehicle was on his ranch and that "in the place where the car was located, some of his belongings were found and there were traces of violence."
Queretaro authorities are investigating, the attorney general's office said.
FThe missing legislator was a senator from PAN, Mexico's National Action Party, and is a former presidential candidate. The statement on Calderon's website called Fernandez de Cevallos "a key politician in the Mexican democratic transition."
- CNN's Esprit Smith contributed to this report.