BUENOS AIRES, Dec. 29 (UPI) -- A man who testified he was tortured by Argentina's former military dictatorship has gone missing, the second witness to disappear in recent months.

Luis Gerez, 50, who has been missing since Wednesday, had testified against a former police chief, accusing him of numerous abuses during the 1976-1983 regime known as the Dirty War, La Nacion reported Friday.

Julio Lopez disappeared earlier this year after testifying against another former police chief.

Some 30,000 people were killed or disappeared during the dictatorship.