By Fiona Ortiz BUENOS AIRES, Dec 29 (Reuters) - Shaken by disappearances of two "dirty war" witnesses in three months, Argentina's government is investigating whether former state agents accused of rights abuses under military rule could be involved. Luis Gerez, a 51-year-old construction worker, vanished on Wednesday, months after testifying in Congress that he was tortured in 1972 by a former policeman who is accused of violating human rights during the 1976-1983 dictatorship. Gerez disappeared 100 days after Jorge Julio Lopez, another construction worker, whose testimony was key in the conviction of a former police commissioner in a landmark human rights trial earlier this year. Lopez is still missing. Leon Arslanian, Buenos Aires province's security minister, said the Gerez investigation would focus on ex-agents. "Our hypothesis takes into account his role as a witness, and what interests were affected. Who are those affected? Former police or military agents who repressed?" he told Radio del Plata radio station. Argentine President Nestor Kirchner personally headed up coordination of the search for Gerez and said the case was an attack on his human rights policy of investigating crimes from the dirty war era. According to official government reports, more than 11,000 people disappeared during the dirty war, when the military government cracked down on leftists and dissidents. But human rights groups put the death toll from the era as high as 30,000. The Supreme Court repealed amnesty laws last year and hundreds of rights cases have been reopened in the courts. Gerez and Lopez are both from populous Buenos Aires province, which rings the capital. They both testified against high-level figures of the notoriously violent and corrupt provincial police, known as the Bonaerense. In a congressional investigation, Gerez testified that when he was 17 in 1972, when Argentina was under military rule, he was tortured by Luis Patti, who later became a high-ranking officer in the force. He also testified that Patti kidnapped leftists during the dirty war. Due to the testimony, Patti, who was elected to Congress in 2005, was barred from taking his seat. Gerez also testified against Patti in a human rights judicial investigation. "Luis was chosen because he was ... someone who declared in public. It's clearly a sign of intimidation," said Alberto Fernandez de Rosa, who was involved with Gerez in local politics with the Peronist Party. Authorities are investigating "anyone from the police, pardoned or let go from the force, or linked with the repressive era," Arslanian said. Lopez's disappearance had prompted calls for government protection of dirty war witnesses, but newspapers said Gerez had not sought protection even though he had received threats. Gerez's children said his car had been vandalized and an unknown man recently threatened him at a bus stop, telling him specific details about his family. Gerez left a friend's house on Wednesday evening to buy meat for a barbecue, leaving behind his car, agenda and mobile phone. The provincial government offered a $130,000 reward for tips on Gerez's whereabouts. (Additional reporting by Lucas Bergman and Damian Wroclavsky)
