Osanloo, the president of the Syndicate of Workers of the Tehran Bus Company, told Radio Farda that charges against him are connected to his union activities.
"They turned a simple case dealing with union and workers problems into a security [issue], which was really not the case," Osanloo said.
Osanloo was released from prison on bail in late December. He was arrested after organizing protests against the working conditions of bus drivers.
Human rights organizations had condemned his arrest.