Iran has taunted the US by appearing to demand a multimillion-dollar ransom to free two prominent Iranian-Americans sentenced to ten years in jail for their links to the West.

Nazanin Zaghari-Ratcliffe, a British-Iranian woman, was sentenced to five years in prison on allegations of planning the "soft toppling" of Iran's government while traveling with her young daughter.

Iranian businessman Siamak Namazi and his 81-year-old father Baquer, a former UNICEF representative who served as governor of Iran's oil-rich Khuzestan province under the U. He was sentenced to 10 years last year on espionage-related charges.

Iranian officials and state media did not immediately report the failed appeal.

The Namazis are among a number of dual nationals held in Iran after the 2015 nuclear deal, which in-part, stated that Iran must significantly reduce its nuclear materials necessary to make a weapon.

Iran is frequently at odds with Israel, despite having the second biggest Jewish community in the Middle East.

DW's Theresa Tropper spoke with the director of Tehran's Jewish Committee, about why that is the case.

Siamak Namazi has spent much of his time in solitary confinement and 'has been interrogated relentlessly, beaten and tased,' according to the Associated Press. citizens still jailed in Iran following a prisoner exchange in January that saw three Americans released, including Washington Post journalist and dual Iranian national Jason Rezaian, according to the LA Times.

'I am deeply worried about the health of both of the Namazis, which has rapidly deteriorated,' Jared Genser said. Jared Genser said Monday that Baquer and Siamak Namazi learned the day before that the Tehran Appeals Court denied their request.

S.-backed shah, are both serving 10-year prison sentences on espionage. permanent resident from Lebanon who advocates for internet freedom and has done work for the U. Former FBI agent Robert Levinson, who vanished in Iran in 2007 while on an unauthorized CIA mission, remains missing as well.

Iranian-American Robin Shahini was released on bail last year after staging a hunger strike while serving an 18-year prison sentence for "collaboration with a hostile government." Shahini is believed to still be in Iran. ___ Gambrell reported from Dubai, United Arab Emirates.

His detention, if confirmed, would make him the latest dual national to be arrested in Iran, part of what a United Nations panel has called an "emerging pattern" since the atomic accord. 21, 2010 file photo, an Iranian security officer directs media at the Bushehr nuclear power plant, with the reactor building seen in the background, just outside the southern city of Bushehr, Iran.