Iranian officials have denied reports opposition leaders Mirhossein Mousavi and Mehdi Karoubi have been arrested.

An unnamed judiciary official told semi-official news agency Fars that the men were in their homes and that there had only been "restrictions on their contacts".

Mr. Mousavi's reformist website Kaleme earlier reported that the men and their wives had been transferred to Heshmatiyeh jail in Tehran.

The International Campaign for Human Rights in Iran also said the two leaders had been moved secretly from their homes.

They had been under virtual house arrest for more than two weeks after calling on supporters to protest against the government on February 14, reports said.