In the midst of the potential nuclear deal, these are the Americans still held in Iran
US President Barack Obama has made calls for Iran to release American prisoners, but so far the Islamic Republic's government has been largely silent.
As world powers and Iran mull a final nuclear agreement, US President Barack Obama and other US representatives have called on the Islamic Republic to release several Americans being held in custody.
In March, he urged Iranian officials to give amnesty to US prisoners in honor of the Nowruz holiday that marks the beginning of the Persian calendar.
So far though, Iran's been pretty quiet on the matter. Here's the roundup of the four Americans in question, and the alleged actions that landed them in Iranian custody.
Jason Rezaian has been held in Iran since July 2014. An Iranian-American dual citizen and the Washington Post's bureau chief in Tehran, was charged with espionage in December 2014 after being detained for more than four months.
Saeed Abedini has been jailed since July 2012. The Iranian-American Christian pastor was sentenced to eight years in prison last year for undermining Iran's national security by setting up Christian churches in his home there.
Iranian-American and former US marine Amir Hekmati was arrested in August 2011 and convicted of spying for the CIA, which his relatives and the U.S. government deny. In December, his lawyer said the US was seeking his release through a prisoner swap. But U.S. State Department spokesman Jeff Rathke later denied these claims.
Then there's the murky case of Robert ‘Bob’ Levinson. In March 2007, the private detective and ex-FBI agent disappeared during a trip to an Iranian island. Iranian Foreign Minister Mohammad Javad Zarif said last December there were no traces of Levinson in Iran and he was not being imprisoned there. The only known proof-of-life video of Levinson appeated in 2010 and featured the American pleaing for the US government to meet the demands of the group holding him. It was traced to an Internet cafe in Pakistan.