TEHRAN: Seven Iranian prisoners held in the United States will be freed in exchange for the release of four Iranian-American nationals jailed in Iran, official media said on Saturday.

Iran's state television named the dual-nationals as Jason Rezaian, the Washington Post's Tehran correspondent, pastor Saeed Abedini, former US Marine Amir Hekmati, and Nosratollah Khosravi.

However, the official IRNA news agency, quoting an informed source, said the fourth person freed was Siamak Namazi, an Iranian-American businessman, before changing its report and naming Khosravi.

The seven Iranians to be freed by the US are Nader Modanlou, Baharam Mekanik, Khosrow Afghahi, Arash Ghahraman, Touraj Faridi, Nima Golestaneh, and Ali Sabounchi, according to Iran's judiciary and the state broadcaster.

Fourteen other Iranians wanted by the FBI would no longer be sought for prosecution by Interpol, both official media outlets said.

Earlier on aturday, Iran said that four Iranian dual nationals had been freed as part of a prisoner exchange in line with national interests on the orders of the country's top security committee.

Saeed Abedini's lawyer, Naser Sarbazi, confirmed to ISNA news agency that his client was released. But Rezaian's lawyer, Leila Ahsan, told AFP she did not know if her client was free.

“I have no information on this,” she said.

The announcement came as Iran and world powers led by the United States were expected to finally implement last July's nuclear deal, which will lift international sanctions imposed on the Islamic republic.