A newspaper editor seen as close to Iran's top authority said Saturday defeated election candidate Mir Hossein Mousavi and a former pro-reform president had committed "terrible crimes" which should be tried in court.

In a commentary published in his hardline Kayhan daily, editor-in-chief Hossein Shariatmadari suggested that Mousavi and his supporters in last month's disputed election had acted on the instructions of the United States, Iran's arch-foe.

The June 12 poll stirred the most striking display of internal dissent in Iran since the 1979 Islamic revolution and strained ties with the West. At least 20 people died in post-election violence last month.

The authorities have portrayed mass pro-Mousavi protests, which erupted after official results showed President Mahmoud Ahmadinejad had been re-elected by a landslide, as the work of local subversives and foreign powers.

They blame Mousavi, a moderate former prime minister, for the bloodshed after the election. Mousavi rejects the charge.

Although hardliners have regained the initiative since security forces quelled the protests, Mousavi and another losing candidate, pro-reform cleric Mehdi Karoubi, have not yielded.

They again denounced the election result Wednesday and said Ahmadinejad's next cabinet would be illegitimate, Reuters reported.