Siamak Namazi, a Dubai-based businessman, was arrested earlier this month while visiting Tehran, according to The Washington Post, which cited an unnamed family friend.
“We’re aware of recent reports of the possible arrest in Iran of a US citizen. We’re looking into these reports and don’t have anything further to provide at this time,” a US senior administration official told AFP.
Three Americans, all of them of Iranian heritage, were already in jail in Iran including Jason Rezaian, a correspondent for The Washington Post who was arrested in July 2014 and accused of spying.
The others are Amir Hekmati, a former US Marine who was charged with spying, and Saeed Abedini, a convert to Christianity who gathered a Bible study group.
An unnamed American businessman was reported arrested by the IranWire website on October 15, and Namazi was afterwards named in tweets by Iranian-Americans, the Post said.
News of the arrest in American media came after US Secretary of State John Kerry met earlier in the day with his Iranian counterpart Mohammad Javad Zarif in Vienna, on the eve of key talks on ending the Syrian conflict.