A prominent Iranian pro-reform journalist and rights activist who was jailed two months ago has been taken to hospital, an Iranian news agency said on Wednesday.

A friend of Emadeddin Baghi said in mid-October he had been jailed for one year of a previously suspended prison sentence for acting against national security and publishing classified documents.

ISNA news agency quoted the general director of prisons in Tehran province as confirming that Baghi was taken to a hospital but that he would be returned to jail on Wednesday evening, without making clear when he was hospitalised or why.

"His general condition was not good and he was taken to one of Tehran's hospitals," the official, Sohrab Soleimani, said.

Baghi, the founder of the Society for Defending Prisoners' Rights, was on Oct. 14 sent to Tehran's Evin prison, where many other dissidents are held, his friend Issa Saharkhiz told Reuters at the time.

A Tehran court found Baghi guilty four years ago of writing critical articles and making speeches about the judiciary's poor treatment of prisoners and cases of defendants being given inadequate access to lawyers, Saharkhiz said.

Rights groups and diplomats say there is a broad crackdown on dissenting voices in the Islamic state, which is under Western pressure over its disputed nuclear programme. The authorities deny such moves, saying they allow free speech.

Baghi was previously jailed for insulting Islamic sanctities. He was released after three years in 2002.

Rights groups often complain that Tehran imprisons pro-reform writers, journalists and intellectuals without due legal process. Iran denies holding political prisoners and routinely dismisses charges of rights abuses.