NEW YORK (AP) ' A Dubai-based businessman has become the fourth Iranian-American to be arrested by Iran's security forces and imprisoned in Tehran, several newspapers reported Thursday.Siamak Namazi, believed to be in his early 40s, was arrested earlier this month while visiting a friend in Tehran, a family friend told The Washington Post. It was not immediately clear whether any charges have been brought against Namazi. The friend asked not to be identified.The U.S. State Department declined to confirm Namazi's arrest."We're aware of recent reports of the possible arrest in Iran of a U.S. citizen. We're looking into these reports and don't have anything further to provide at this time," Michael Tran, a State Department spokesman, said late Thursday.Namazi, the son of a former governor in the oil-rich Iranian province of Khuzestan, comes from a prominent Iranian family, which came to the United States in 1983 when he was a boy, according to The Washington Post.Namazi's arrest ' which was also reported by The New York Times and The Wall Street Journal ' suggests that hard-liners in Iran could be trying to create tension with the United States in the wake of Iran's nuclear deal with world powers. That agreement reached earlier this year promises Iran relief from crippling economic sanctions in exchange for curbs on its nuclear program.Iranian hard-liners are opposed to moderate President Hassan Rouhani's strategy of attempting to improve ties with the West. Internal domestic struggles over the direction of Iran appear to be intensifying ahead of February's parliamentary elections.The Washington-based National Iranian American Council said it was troubled by reports of Namazi's arrest and denied suggestions that his family had a leadership role in the organization, through it acknowledged "Namazi has known members of NIAC's staff.""NIAC is very concerned by the continued detention of multiple Iranian Americans by the Iranian government, and is deeply troubled by the reports that Mr. Namazi may also have been detained," it said.The arrest of an unnamed Iranian American businessman was first reported by IranWire, an online publication, on Oct. 15.According to The Wall Street Journal and The New York Times, Namazi is head of strategic planning at Crescent Petroleum Co. In the past few weeks, Iranian businessmen with links to foreign companies have been detained, interrogated and warned against becoming involved in economic monopolies controlled by the Revolutionary Guard Corps, The Wall Street Journal reported, citing businessmen inside and outside of Iran. The Times quoted unnamed people close to Namazi.An official at Crescent Petroleum, which is based near Dubai in the Emirati city of Sharjah, said he had no information and did not confirm Namazi's employment when reached by The Associated Press this week. He later referred questions to an outside public-relations firm that did not respond.A consulting company in Iran with which Namazi previously had ties, Atieh Bahar, denied to AP that he had any ongoing role there. An official, who refused to be identified, said Namazi had not worked with the firm "for eight or ten years."Washington Post reporter Jason Rezaian was convicted by the country's Revolutionary Court on charges including espionage without providing details on the verdict or sentence. He was detained in July 2014 and has now been held longer than the 52 American diplomats and citizens who were held hostage in Iran for 444 days from late 1979 to early 1981.Former Marine Amir Hekmati, who holds dual Iranian and American citizenship, was arrested in August 2011. And Saeed Abedini, a pastor from Boise was convicted in 2013 of threatening Iran's national security by participating in home churches.___Associated Press writer Adam Schreck in Dubai, United Arab Emirates, contributed reporting.Join the conversation about this story Click here to read full news..