Iranian-American businessman 'detained in Iran'

The reported detention comes despite a thawing in relations in recent months

An Iranian-American businessman has been detained by authorities in Iran, reports say.

Siamak Namazi was held earlier this month while on a visit to Tehran, sources told BBC Persian.

He was detained by intelligence agents and is being kept in solitary confinement at Evin prison, according to a source quoted by Reuters.

If confirmed, it would be the latest of several detentions by Iran of people with dual Iranian-American nationality.

The US state department said it was looking into the reports of Mr Namazi's arrest.

It comes despite a thaw in relations between Iran and the West - including a deal on the country's nuclear programme.

Iran is also attending talks on the Syrian civil war for the first time this week.

Charges unclear

Mr Namazi - who was said to be based in Dubai and to have been working for a UAE oil and gas company - was barred from leaving Iran in July, the Reuters report said.

He was questioned regularly before being detained in mid-October, it added.

It is unclear what charges, if any, he faces.

Jason Rezaian has been detained for more than a year

Other cases involving men with dual American and Iranian nationality include:

• Washington Post reporter Jason Rezaian, 39, has been held for more than a year on charges including espionage that the paper calls absurd. A verdict was issued earlier this month - officials did not give details but hinted at a conviction

• Saeed Abedini was jailed in 2012 after being accused of setting up a Christian prayer network in private homes

• And Amir Mirzai Hekmati has been held since 2011, accused of being a CIA spy. US Secretary of State John Kerry has said the charges are false. He has appealed to Iran to release both Mr Hekmati and Mr Abedini.