An Iranian opposition leader who has been under house arrest since 2011 has asked President Hassan Rouhani to lobby for an open trial.

Mehdi Karroubi says he wants to publicize new details about fraud in the 2009 presidential election, in which Mahmoud Ahmadinejad defeated Karroubi and another prominent opposition figure to secure a second term. The election was marred by allegations of fraud and was followed by massive protests.

Karroubi, 78, and the other opposition candidate, Mir Hossein Mousavi, have been under house arrest since 2011. They have not been formally charged with anything.

An opposition website reported Saturday that Karroubi had sent a letter to Rouhani communicating his request.

Rouhani, a political moderate elected in 2013, can press for open trials.