An Iranian woman has been sentenced to 10 years in prison after being accused of spying for the UK.
According to judiciary spokesman Gholamhossein Esmaili, the unnamed woman confessed to "co-operating" with British intelligence.
Mr Esmaili said the woman was in charge of the Iran desk of the British Council, leading some to suggest she was Aras Amiri.
The London-based British Council employee and art student was detained in Iran in March 2018.
"The person travelled to the country [Iran] using a false name in order to implement design, plan and lead various projects regarding the implementation of the cultural objectives of the old colonialism [UK] inside Islamic Iran," Mr Esmaili said at a press conference today.
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"The person was involved in contacting theatre and art groups to implement that very issue of cultural infiltration or cultural ambush."
Mr Esmaili said such actions "drew the attention of Iran's security and intelligence services", which led to the woman's arrest last year.
He claimed she confessed to the charges "very quickly" at trial.
The foreign office in the UK said it was "very concerned" following reports of the imprisonment.
"We have not been able to confirm any further details at this stage and are urgently seeking further information," a British Foreign Office spokeswoman said.
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The husband of incarcerated charity worker Nazanin Zaghari-Ratcliffe called the jail term a "real slap in the face".
Mrs Zaghari-Ratcliffe is part-way through her own five-year sentence after being accused of spying by Tehran's Islamist regime, a charge she vehemently denies.
Speaking after the alleged spy was sentenced, her husband Richard Ratcliffe told the Press Association: "It is outrageous, really - the UK needs to step up and protect citizens.
"Nazanin called me last night to say that somebody was being taken down from the cells to be sentenced by the judge.
"She was very despondent."
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He added: "It's a clear example of hostage diplomacy not being there. Diplomatic protection needs to show that it means something.
"To be fair, the court process is nonsense and the health process is nonsense.
"This is about making it clear to the UK that Nazanin and others are being held as bargaining chips."
The chief executive of the British Council, Sir Ciarán Devane, said the employee detained last year was not the head of the Iran Desk as suggested, but someone in a junior role who showcased the "Iranian contemporary art scene to UK audiences."
He added: "We have seen reports that an Iranian national, claimed to be an employee of the British Council, has been sentenced.
"However we have not been able to confirm that this is our colleague.
"Our colleague's safety and wellbeing remain our first concern, as it has been throughout their detention."
Last month Iran's foreign minister suggested Mrs Zaghari-Ratcliffe could be released as part of a prisoner swap.
However, he subsequently backed down from the suggestion.
Mr Hunt has already granted her diplomatic protection.
But Tehran refuses to acknowledge her dual nationality and said the UK's actions were illegal."
