Washington, United States – A deal brokered by Oman, Qatar and Switzerland has led Iran to move five Americans from jail to house arrest.

This is the first step of a delicate deal that would unfreeze billions of dollars in Iranian funds and allow the prisoners to leave the Islamic republic.

The progress on the prisoners – one of them detained for nearly eight years – comes after quiet, exhaustive diplomacy between the long-time adversaries whose separate talks on restoring a nuclear deal broke down.

“My belief is that this is the beginning of the end of their nightmare, and the nightmare that their families have experienced,” US Secretary of State Antony Blinken told reporters.

Sources familiar with the negotiations said the next step would be the transfer of US$6bn in Iranian oil revenue frozen in South Korea to a special account in Qatar which Iran could access only for humanitarian purchases such as food and medicine.

In an Al-Monitor interview, an independent Middle East news and analysis website based in Washington DC, USA, in June, H E Sayyid Badr al Busaidi, Foreign Minister, said Washington and Tehran were “close” to finalising a deal on the release of Americans held in the Iranian capital.

“I can say they are close,” he said of a likely prisoner agreement. “This is probably a question of technicalities.” He said Oman has “offered in good faith our offices to help both sides, be it here or anywhere else”.

Iran described the deal as a prisoner swap, with the state-run IRNA agency quoting Tehran’s mission to the United Nations as saying that each country will be “granting amnesty and releasing five prisoners”.

If all goes as planned, the American prisoners could leave Iran sometime in September, one source said on condition of anonymity.

Four of the prisoners – Siamak Namazi, Emad Sharqi, Morad Tahbaz and the fourth who preferred to remain anonymous – were taken out of Tehran’s Evin prison on Thursday, a day after President Joe Biden’s administration informed their families of the deal.

The four were escorted to a hotel where they will remain held under guard, a lawyer for one of the prisoners said.

Sources said that a fifth American, a woman, is also part of the discussions and has already been moved in recent weeks to house arrest.

“While this is a positive change, we will not rest until Siamak and others are back home; we continue to count the days until this can happen,” Babak Namazi, Siamak’s brother, said in a statement.

At the centre of discussions has been the unblocking of US$6bn that Iran earned selling oil to South Korea. Seoul blocked the funds to comply with US sanctions imposed under former president Donald Trump that hit the Iranian economy hard.

While stressing that the arrangement was not final, sources said the funds would be converted from won to euros and administered by Qatar, which played a key mediatory role. No funds would be transferred directly to Iran.

Iranian state media said the prisoners would only be released once the money was deposited.

Agencies