TEHRAN: British-Iranian national Nazanin Zaghari-Ratcliffe appeared in a Tehran court Sunday to face new charges of "propaganda against the system", a week after she finished serving a five-year sentence, her lawyer said.

"The hearing took place in a very calm and good atmosphere, in the presence of my client," Hojjat Kermani told AFP, adding that the judgement would be handed down at a later and unspecified date.

According to Kermani, the 42-year-old dual national was prosecuted for "propaganda against the system for having participated in a rally in front of the Iranian embassy in London" in 2009.

"Given the evidence presented by the defence and the legal process, and the fact that my client has also served her previous sentence, I hope that she will be acquitted," the lawyer added.

Zaghari-Ratcliffe was detained while on holiday in 2016 and convicted of plotting to overthrow the regime in Tehran -- accusations she strenuously denied.

She has been under house arrest for months and had her ankle tag removed, giving her more freedom of movement and allowing her to visit relatives in Tehran.

She completed her sentence on March 7.

A day later, her husband, Richard, and their six-year-old daughter, Gabriella, held a vigil outside the Iranian embassy in central London demanding she be allowed home.

He tried to deliver an Amnesty International petition signed by 160,000 supporters calling for his wife's release, but was turned away.