An Iranian woman who worked for the British Council was sentenced to 10 years in prison for "spying," the judiciary's news website Mizan Online reported Monday, sparking concern in London.

"An Iranian citizen in charge of the Iran desk at the... British Council was cooperating with English spying agencies," Mizan reported, quoting judiciary spokesman Gholamhossein Esmaili.

He did not identify the suspect, but said she had been sentenced recently after she "made a straightforward confession."

Esmaili added that the suspect, who had been tasked with drawing up and managing cultural "infiltration" projects, had been arrested by Iranian intelligence and security agencies "more than a year ago."

The United Kingdom's foreign ministry voiced concern over the sentence.

"We are very concerned by reports that an Iranian British Council employee has been sentenced to jail on charges of espionage," a spokesperson for the Foreign and the Commonwealth Office told AFP.

"British Embassy officials in Tehran are in touch with the Iranian government to seek further information."

The British Council is a cultural and educational organization with branches around the world, but according to its website, it is not "physically present" in Iran.

Iranian authorities shut down the British Council more than a decade ago for what Esmaili described as "illegal activities."

Esmaili said that during her confession, the suspect described how she had been recruited, telling investigators about the instructions she had been given by "the English security agency."

The spokesman said that she was "an Iranian student who wanted to live and work in the UK," was hired by the British Council and "repeatedly traveled to Iran under aliases... and made connections with artistic and theater groups."

A London-based British Council employee was arrested in Iran in 2018 during a trip to visit relatives.

It was not immediately clear if she was the person sentenced on Monday.

The sentencing comes amid tensions between Iran and Britain over the fate of British-Iranian mother Nazanin Zaghari-Ratcliffe who was arrested by Iranian authorities in 2016 as she was leaving Tehran.

Zaghari-Ratcliffe, who worked for the Thomson Reuters Foundation, was put on trial and is now serving a five-year jail sentence for allegedly trying to topple the Iranian government.