The British Council says an Iranian employee who was accused of spying by Iran has been released from detention there and has returned to the UK.
Aras Amiri had been acquitted of all charges by Iran's Supreme Court following an appeal, the cultural organisation said in a statement.
There was no immediate confirmation from the Iranian authorities.
Ms Amiri, who worked in the British Council's London office, was arrested in 2018 while visiting her grandmother.
A spokesman for Iran's judiciary announced in 2019 that an Iranian woman "in charge of the Iran desk at the British Council" had been convicted of spying by a Revolutionary Court and sentenced to 10 years in prison.
He alleged that the woman had used contacts with arts and theatre groups to "influence and infiltrate" Iran at a cultural level, and that she had confessed to co-operating with British intelligence.
Both Ms Amiri and the British Council denied the charges, and her British fiancé accused Iran of using her as a "bargaining chip" in its wider diplomatic disputes with the UK - something officials in Tehran deny.
She was held in the same prison as British-Iranian charity worker Nazanin Zaghari-Ratcliffe and a number of other Iranians with dual nationality or foreign permanent residency convicted of spying and other security-related offences in recent years.
Reading the runes
By Caroline Hawley, BBC diplomatic correspondent
News of Aras Amiri's release is being followed closely by relatives of the British-Iranian dual nationals being held in Iran. They include Nazanin Zaghari-Ratcliffe, the retired engineer Anoosheh Ashoori, and the environmentalist Murad Tahbaz.
Reading the runes of what this might mean for them is not easy. Some context: her return to the UK comes as Iran is negotiating with world powers in Vienna in an effort to revive a 2015 nuclear deal. Tehran recently said it had also been discussing with the UK its £400m ($548m) debt for an abandoned tank deal.
The UK Foreign Office is not commenting on Ms Amiri's release. But Mrs Zaghari-Ratcliffe's husband, Richard Ratcliffe, said he was very happy for her and her family.
"We hope it is a good sign for the rest of us. Though across all the British cases the signals are mixed, with some potential new releases alongside some potential new cases."
He added: "We are watching closely what happens in the negotiations in Vienna, to see what that means downstream for us."
"We have always refuted the original charges made against Aras," the British Council said on Wednesday.
"We are very proud of her work in our London office as an arts programme officer supporting a greater understanding and appreciation of Iranian culture in the UK. This was important work which reflects the value of cross-border cultural collaboration.
"Aras' well-being remains our priority and we ask that her privacy is respected as she rebuilds her life in the UK following a long and difficult period."
Ms Amiri's Iranian lawyer, Hojjat Kermani, told the Associated Press that Iran's Supreme Court had determined that her spying conviction was "against Sharia", or Islamic law.
She left Tehran for the UK on Monday but had been free from prison in recent months as she appealed against a travel ban, Mr Kermani said.
In a separate development on Wednesday, Iran re-imprisoned a French-Iranian academic who had been sentenced to prison but was recently living under house arrest.
Fariba Adelkhah received a five-year sentence for allegedly conspiring against national security and one year for propaganda in May 2020.
A spokesperson for the French foreign ministry condemned her detention and warned the move could "only have negative consequences on the relationship between France and Iran and reduce the trust between our two countries".