The charge carries the death sentence in the Islamic republic.
Elham was quoted by Iran's hard-line Fars news agency as saying during a speech at a university that although he confirmed Musavi's candidacy to run during last year's presidential election, he now believes the former prime minister is an enemy of the Iranian system.
Elham added that he feels sorry for those who still support Musavi, because "he's led to the disruption of order in the country, street terror, and similar issues."
The Iranian official said that his view is a legal viewpoint and does not carry any executive weight.
Elham, a former government spokesman and a former minister of justice, and his wife, hard-line journalist Fatemeh Rajabi, are known as staunch supporters of President Mahmud Ahmadinejad.
-- Golnaz Esfandiari