Iran has released a Lebanese businessman imprisoned on charges of spying for the United States.
Nizar Zakka, who is a US permanent resident, arrived in Beirut on a plane with the head of Lebanon's General Security directorate, Abbas Ibrahim.
The information technology expert was arrested while visiting Tehran in 2015 and was subsequently sentenced to 10 years in jail for anti-state activity.
Zakka was freed following a request by Lebanon's President Michel Aoun.
But Iranian state television cited official sources as saying that his release was secured only after Hassan Nasrallah, the leader of the Iran-backed Lebanese Shia Islamist militant group Hezbollah, intervened.
Zakka is one of a number of dual citizens and foreign nationals detained in Iran, mostly on spying charges, in recent years. The Americans being held include:
- Baquer Namazi and Siamak Namazi - the former UN official and his son, a businessman, were both sentenced to 10 years in prison in 2016
- Karen Vafadari and Afarin Neyssari - the Zoroastrian couple, who own an art gallery, were sentenced to 15 and 10 years in prison in 2018
- Xiyue Wang - the doctoral student conducting historical research was sentenced to 10 years in prison in 2017
- Morad Tahbaz - the environmental activist was arrested in 2018
Zakka, who is in his 50s, is an advocate for internet freedom and is secretary-general of the Beirut-based Arab ICT Organisation (IJMA3), an alliance of information communications technology associations from 13 countries across the Arab world that has worked for the US government.
In September 2015, he travelled from his home in Washington DC to Tehran to attend the International Conference and Exhibition on Women in Sustainable Development.
He had been invited to speak by Iran's then Vice-President for Women and Family Affairs, Shahindokht Molaverdi.
Zakka was arrested while on his way to the airport to leave the country by men believed to belong to the Revolutionary Guards and was transferred to Tehran's Evin prison, where he was kept in solitary confinement for almost a year.
In October 2016, the judiciary said Tehran's Revolutionary Court had sentenced Zakka to 10 years in prison for co-operating with a foreign enemy state - an allegation rejected by his family. An appeals court upheld the sentence at the end of 2017.
Last September, Ms Molaverdi told the Associated Press that the government of President Hassan Rouhani, a moderate, had "in no way approved" Zakka's prosecution by the hardline judiciary.
"We did all we could to stop this from happening, but we are seeing that we have failed to make a significant impact," she said.
Last week, it emerged that Lebanon's president had asked the Iranian authorities to pardon Zakka as a gesture to mark the end of the Islamic holy month of Ramadan.
On Tuesday, Iranian judiciary spokesman Gholamhossein Esmaili announced that the relevant court had agreed to Zakka's conditional release because he had served at least a third of his sentence and shown good behaviour.
Mr Esmaili revealed Iranian officials had been told by Hezbollah's leader that the move would be "expedient", but he insisted "no political issue has been involved", the judiciary's Mizan Online news agency reported.