The lawyer for an Iranian-American journalist prevented from leaving Iran says his client is facing a new charge of acting against Iran's national security.

Parnaz Azima (Radio Free Europe image)

The lawyer for Parnaz Azima told U.S.-funded Radio Farda that Iranian authorities have given no indication when the Radio Farda journalist can leave Iran.

Azima is already facing charges of working with Radio Farda and spreading propaganda against the Iranian state.

Azima traveled to Tehran in January to visit her sick mother, but has been prevented from leaving.

Last week, Iran released on bail an Iranian-American academic who has been jailed in Tehran since May on security charges. Haleh Esfandiari is a Middle East expert for the Woodrow Wilson Center.

Two other Iranian-Americans - urban planner Kian Tajbakhsh and Ali Shakeri, who works for a university conflict-resolution group - are also being held.