▶ Watch Video: Family says Iran imprisoning husband over “bogus” charges, pleads for White House to bring him home Emad Shargi, one of four Americans being held prisoner in Iran as discussions are underway that may return the U.S. to a nuclear agreement with Iran, was suddenly arrested in November, just weeks after Joe Biden won the presidential election. In an exclusive interview with CBS News, the family of the 56-year-old businessman revealed new details about his arrest. Shargi’s daughters — Hannah and Ariana — were emphatic in their conviction that their father was taken in order to be used as leverage by Iran over the Biden administration. “It’s because he’s an American citizen,” Hannah Shargi told CBS News. “And there are three other detainees — the Namazis and Mr. Tahbaz — who are currently there who are American citizens, as well. And they’re all innocent. They have committed no crimes. And the only reason that they were taken is because they’re American citizens — to be used as leverage.” Bahareh Shargi, Emad’s wife, told CBS News that he is being denied access to his attorney and that the Swiss diplomats who represent the U.S. in Iran have also not been permitted to have consular access to him. Shargi was born in Iran but is a U.S. citizen. “In fact, it’s been four months that not a single soul has seen Emad. Even his lawyer has asked to see him numerous times and has not been allowed to see him,” Bahareh told CBS News in an interview at her family’s Washington, D.C., home. Shargi’s wife and daughters also revealed that Shargi suffers from ongoing health problems that require medical attention and medication. They fear that he is at risk of contracting COVID-19 while he’s incarcerated in wing 2A of Tehran’s notorious Evin Prison but hope he remains healthy and safe. Shargi has, however, been permitted occasional phone calls with his family, though Iranian government minders listen in. His wife has made a habit of keeping her phone with her at all times in case he is allowed to call them. The Biden administration is doing “everything we can,” a senior administration official told CBS News, on behalf of the four U.S. prisoners being held in Iran but declined to confirm that the hostage issue has been raised during the ongoing shuttle diplomacy in Vienna regarding the U.S. return to the international nuclear agreement known as JCPOA, the Joint Comprehensive Plan of Action. Shargi’s wife and children told CBS News that if any progress has been made regarding a potential prisoner swap or release, it has not been made clear to them. Bahareh Shargi hopes to meet soon with Special Envoy Rob Malley who is currently in Vienna for the nuclear talks. She and the family members of other hostages met virtually with Secretary of State Antony Blinken in January. The State Department insists that prisoners are a “significant priority” but Bahareh Shargi urged them to make prisoners the top priority. “Nuclear talks are big, and they will take some time. But families like ours are just these little families living our lives. Just release Emad,” she told CBS News. National security adviser Jake Sullivan first revealed on “Face the Nation” in February that the Biden administration had already reached out to Iran about the hostages. At the time, Sullivan said the U.S. had “begun to communicate” with the Iranians, but sources told CBS News that the offer fell flat. Iran’s foreign minister subsequently said that the country is open to the idea of a prisoner swap, but so far that general statement does not appear to have resulted in any active diplomacy. Sullivan: Biden ready for Iran talks, vows re… 08:17 Sullivan’s public statement was made around the same time that the U.S. officially made the offer to begin these so-called “proximity talks” regarding the possibility that the U.S. could rejoin the nuclear deal. Bahareh Shargi explained that she and her husband had left Iran as children and had just been visiting the country as tourists three years ago when their ordeal began. “Our family has been torn apart. My husband has been taken from us for the past three years,” she said. “I don’t think that this is the right way to treat people that come to visit this country, especially perhaps — no, not especially, anybody. But it just happens to be that we were born in that land. And we came back to get to know this land better.” The State Department considers Emad Shargi to be “wrongfully detained” along with three other Americans including Siamak and Baquer Namazi. In a statement from a senior State Department official to CBS News, the official said, “The focus was on these steps, but we did raise — as we do every time we have an opportunity — the case of detainees and missing persons — and we raised it as forcefully as we always do just as Iran can understand that is our priority.” “It is separate from the talks, but just so Iran knows, it is not something we forget,” the official added.