A British journalist has been arrested in Iran as part of a crackdown on foreign media.

The Washington Times reporter - who has joint British and Greek nationality - is believed to be Iason Athanasiadis-Fowden, who is also known as Jason Fowden.

He was arrested as he was attempting to leave the country at the end of last week, a culture ministry official said.

The British Foreign Office said it was aware of the journalist's arrest and understood that Greek officials were providing consular assistance.

"We, of course, stand ready to help if needs be," a spokeswoman for the department said.

Mr Fowden had been sent to Iran to cover the disputed election.

In a statement on the Washington Times website, executive editor John Solomon said: "We have been trying diligently to ascertain Iason's whereabouts. We understand that the Greek foreign ministry and the Greek ambassador in Tehran are diligently working to secure his swift release.

"We hope the situation will be resolved very soon."

The Iranian crackdown of foreign media has seen a number of reporters, including a BBC correspondent, expelled from the country.

EU foreign policy chief Javier Solana hit out at the suppression of press reports, describing it as "not something we can accept".

The Foreign Office said that as far as they were aware Mr Fowden is the only journalist with British links so far arrested in Iran during the recent unrest.

Tensions between Iran and the West have increased after claims that anti-government protesters holding British passports have been arrested.

On Wednesday, riot police and protesters clashed in the streets around Iran's parliament as hundreds of people converged on a Tehran square in defiance of government orders banning demonstrations.

It followed a declaration by the country's supreme leader that the government would not yield to the opposition.

Ayatollah Ali Khamenei accused Britain, the US and other foreign powers of being behind the street protests.

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