Iran Hassan Rouhani Austria visit
Iranian President Hassan Rouhani has spoken to British Prime Minister Theresa May about the detention of dual nationals Handout via Reuters

Iran has arrested a British citizen on suspicion of spying for British intelligence services, it has been reported. The individual – who also holds Iranian nationality – has not been named.

Tehran prosecutor general Abbas Jafari-Dowlatabadi was quoted by IRNA news agency as saying the detainee had been "active in the economic field, related to Iran." The arrest reportedly took place last week and adds to the string of detentions of dual nationals by Iran's Revolutionary Guards for alleged security violations.

A Foreign Office spokesman was quoted by ITV news as saying: "We are seeking information following the reported detention of a dual Iranian-British national in Iran."

At least six other British, Canadian and US dual nationals have been arrested in the country in recent months including British-Iranian charity worker, Nazanin Zaghari-Ratcliffe. The 37-year-old was arrested in the Iranian capital in April on her way back to the UK with her two-year-old daughter after a holiday.

The charges against Zaghari-Ratcliffe have not been specified, according to the BBC. She is accused of trying to topple the regime in Iran and she has previously been slapped with allegations of leading a "foreign-linked hostile network".

The British-Iranian charity worker has hit out at her arrest. She said: "The idea that anyone with a baby could be busy overthrowing the regime is obviously nonsense." Her husband, Richard Ratcliffe, said she had been "caught up" in a political game which is being played out in the Iranian government.

Zaghari-Ratcliffe had been placed in solitary confinement during the first two months of her detention. The ordeal left her unable to "walk without blackouts and her hair was falling out," her husband told the BBC.

Iran does not recognise dual nationality, meaning those who have been held have not had access to foreign officials and face trial in the Revolutionary Court behind closed doors.

British Prime Minister Theresa May spoke to Iranian President Hassan Rouhani last week to discuss advancing ties between the two countries. May also raised concerns over a number of consular cases, including that of Zaghari-Ratcliffe.