State Department spokesman Sean McCormack says Washington has received reports in the past week that are consistent with allegations of Ganji's mistreatment by Iranian authorities.
"Mr. Ganji has spent more than five years in prison due to his peaceful advocacy for free speech and democracy. His imprisonment and any inhumane treatment are serious violations of fundamental human rights," McCormack said. "The United States calls for the immediate and unconditional release of Akbar Ganji as well as his immediate access to medical assistance and legal representation."
McCormack called for continued international pressure on Iran to release all political prisoners.
Ganji was jailed in 2000 after writing a series of articles linking senior officials to the murder of political dissidents.