Son of defeated Iran candidate ally killed: website

"Mohsen Ruholamini, the son of Abdolhossein Ruholamini who was a top advisor to Mohsen Rezaie, was killed in Evin prison," the Mosharekat website said.

It did not say how Ruholamini was killed or when, and the authorities were not immediately available to confirm the death or comment on the circumstances surrounding it.

Ruholamini was arrested in post election protests on July 9, and held in Evin, the website said.

"His family was told that Mohsen will be released soon. But the authorities informed the family on Thursday night about his death," the website said.

Rights groups say hundreds of people, including senior pro-reform activists, journalists, academics and lawyers, have been arrested since Iran's disputed June 12 presidential vote.

Defeated candidates say the election was rigged in favor of President Mahmoud Ahmadinejad. Iran's top authority Supreme Leader Ayatollah Ali Khamenei endorsed the president's election victory soon after the vote.

The election has plunged the country into its biggest internal crisis since the 1979 Islamic revolution and has exposed deepening divisions in its ruling elite.

Leading moderates, including former presidents Mohammad Khatami and Akbar Hashemi Rafsanjani, have called for immediate release of post-election detainees.

The authorities say most of those held have been freed.

Iranian official media have said at least 20 people died in violence after the poll.

Human right groups have reported of several cases of protesters' death, including the 19-year-old Sohrab Aarabi, who they say was killed during demonstrations after the vote.

Moderate defeated candidate Mirhossein Mousavi and the authorities blame each other for the bloodshed. Riot police and religious Basij militia eventually suppressed June's protests, but leading moderates have remained defiant, calling the new government "illegitimate."

Mousavi has said he will join a planned group of leading figures to preserve "people's votes," saying he would not allow his killed supporters' "blood to be trampled."

(Editing by Jon Boyle)