An Iranian American businessman who has been imprisoned in Iran for nearly seven years has been released from Tehran’s Evin prison on a one-week, renewable furlough, the United Nations announced on Saturday.

The release of detainee Siamak Namazi comes as his father, Baquer Namazi, is being allowed to leave Iran for medical treatment, UN spokesperson Stephane Dujarric said in a statement.

“The [UN] secretary general is grateful that, following his appeals to the president of the Islamic Republic of Iran, our former colleague Baquer Namazi has been permitted to leave Iran for medical treatment abroad,” Dujarric said.

Baquer Namazi is the ex-governor of Iran’s Khuzestan province and former representative of what was originally known as the United Nations International Children’s Emergency Fund (Unicef).

“The secretary general is also pleased to learn that Baquer Namazi’s son, Siamak Namazi, has been released from detention,” Dujarric continued. “We will continue to engage with the Iranian authorities on a range of important issues, including the regional situation, sustainable development and the promotion and protection of human rights.”

Baquer Namazi was convicted in Iran of “collaboration with a hostile government” in 2016 and sentenced to 10 years in prison. Iranian authorities released him on medical grounds in 2018 and closed his case in 2020, commuting his sentence to time served but effectively barring him from leaving the country.

His son, Siamak, was convicted of the same charge and has been held in Evin prison since 2015. The US government has described the charges against both as baseless.

It was unclear if Siamak’s furlough might be a step toward his full release. It was also not clear whether it signals the possible furlough or release of other US citizens detained in Iran.

“I am thrilled for the Namazi family that for the first time in seven years Siamak Namazi is sleeping at home with his family,” the attorney who represents the Namazi family, Jared Genser, told Reuters.

Genser added that Siamak Namazi was staying with his parents at their Tehran apartment.

“This is a critical first step but of course we will not rest until the entire family is able to return to the United States and their long nightmare is finally over,” Genser also said.

Their release coincides with the height of intense protests against the Iranian regime following the death of Mahsa Amini, a 22-year-old woman who was allegedly beaten by Iran’s morality police over headscarf laws.

Iran’s semi-official news agency Nournews on Saturday reported that a regional country has helped Iran and the US mediate for the “simultaneous release of prisoners,” shortly after Tehran allowed Siamak Namazi out of prison on a one-week furlough.

“In recent weeks, intensive talks, with the mediation of a regional country were held for the release of Iranian and American prisoners,” the news agency said, without disclosing which country was the mediator.

The news agency also said that billions of dollars of Iranian assets frozen by US sanctions would “be released soon”.

Iran said in August it was ready to swap prisoners with the United States after the American secretary of state, Antony Blinken, tweeted that “Siamak Namazi had now spent 2,500 days wrongfully detained” in Iran. According to Blinken, Washington was determined to secure the freedom of all Americans held by its Middle East adversary.

Tehran has sought the release of a dozen Iranians held in the United States, including seven Iranian-American dual nationals, two Iranians with permanent US residency and four Iranian citizens with no legal status in the United States.

Reuters contributed reporting