Iran's top security body has approved the release of opposition figures Mir Hossein Mousavi and Mehdi Karroubi, under house arrest for seven years for leading mass protests in 2009, a family member told local media.
"I have heard that the decision to lift the house arrest was approved by the Supreme National Security Council," said Hossein Karroubi, son of the jailed reformist, according to the Kalameh news website which is close to the family.
"This decision will be presented to the (supreme) leader so that this case can be concluded," he said, adding that Ayatollah Ali Khamenei would have 10 days to veto the decision.
There was no official confirmation of the decision, but the reports come at a time when Iran's leaders are keen to unite conservative and reformist factions to face down increasing pressure from the United States and a worsening economic crisis.
Mousavi, 76, and Karroubi, 80, were reformist candidates in the controversial election of 2009, which was won by hardliner Mahmoud Ahmadinejad.
They claimed the vote was rigged, triggering months of mass protests, particularly in Tehran. Hundreds of thousands took to the streets in the biggest challenge to the system since the Islamic revolution of 1979.
The pair were placed under house arrest without trial in February 2011, along with Mousavi's high-profile wife, 66-year-old Zahra Rahnavard.
Hossein Karroubi said the security council had also agreed to lift restrictions on reformist figurehead Mohammad Khatami, who was Iran's president from 1997 to 2005.
The media had been banned from showing Khatami's face and strict limits were placed on his movements.
President Hassan Rouhani repeatedly vowed to seek the release of Mousavi and Karroubi -- a major plank of his election in 2013 and re-election last year, with their names frequently chanted at his rallies.
But despite Rouhani chairing the Supreme National Security Council, which is made up of government and military figures appointed by the president and supreme leader, there had been no sign of progress on their release.