An Iranian employee of the British Council arrested in Tehran and later sentenced to 10 years in prison over internationally criticized espionage charges has been freed and traveled to the United Kingdom, the organization said Wednesday.

Iranian authorities did not immediately acknowledge the release of Aras Amiri. However, it comes amid ongoing negotiations in Vienna between Iran and world powers, including the UK, over its tattered 2015 nuclear deal.

The British Council said Wednesday that an appeal her lawyers made to Iran’s Supreme Court had been successful. Amiri worked for the council’s London office.

“We have always refuted the original charges made against Aras,” the council said in a statement. “We are very proud of her work in our London office as an arts program officer supporting a greater understanding and appreciation of Iranian culture in the UK”

In Tehran, her lawyer, Hojjat Kermani, confirmed that Amiri had been released in an interview with The Associated Press. He said Iran’s Supreme Court had determined that her earlier espionage conviction in the country’s Revolutionary Court was “against Shariah,” or Islamic law. He did not elaborate.

Kermani said she left Tehran on Monday but had been free from prison in recent months as she appealed a travel ban.

Iran announced her conviction in 2019. Authorities there accused her of spying on cultural activities in Iran. The British Council previously said she traveled to Tehran to visit family on a private trip that didn’t involve her work at the nonpolitical organization that works in arts, culture and education.