A former FBI agent the US government claimed had gone missing in the Iranian island of Kish has returned to his country amid news black out.

The US National Security Agency had said that Former FBI Agent, Robert Levinson, had been arrested following a meeting with a former US citizen on the Iranian Island of Kish on March 8, and was detained by Iranians until Sunday.

"The Iranian officials have concluded that he was merely a businessman with no ill intentions toward Iran, said a source in the Agency.

The US National Security Agency reportedly received the news of his release early on Monday, US time.

MJ/AVA