Relatives of dual nationals incarcerated in Iranian jails called on their governments to declare a hostage crisis with the country on Tuesday at the launch of a new international alliance to free those held by the Tehran authorities. Leading members of the Alliance of Families Against Hostage Taking accused the Iranian officials, including the foreign minister, of manipulating their tragedy in media appearances in which prisoner swaps are raised as a condition of release. The Alliance believes Tehran's decision to promise prisoner swaps demonstrates the victims are being held as hostages. “Look at it from outside and see it is hostage taking,” said Ali Rezaian, the brother of journalist Jason Rezaian who was held for a year and a half in Iran. “Say what it is — say to our government you need to get them out. There should not be any concessions to Iran while people are held as hostages.” The group was speaking at a press conference on the sidelines of the United Nations General Assembly meeting in New York. Richard Ratcliffe, the husband of the British-Iranian woman Nazanin Zaghari-Ratcliffe, said that Iran hides behind its justice system to cast doubt on the cases the families raise. “There is a real reluctance to say what’s going on here. Iran is playing off people in various ways that builds the hostage industry,” he said. “There’s a false symmetry in that it’s not a legal system in Iran, it’s a placebo for justice.” Babak Namazi, the son of Baquer Namazi, 81, said he feared for the worse if his father, who is in failing health is not released soon. To see Mohammed Javad Zarif, the foreign minister talk of prisoner swaps only intensified the anguish of the relatives. “It’s very painful when Mr Zarif comes and makes these statements. As family members we go on this roller coaster,” he said. “I want my relative to come home and come home before a tragedy happens.” Mr Zarif told America’s National Public Radio that a Chinese American professor, Xiyue Wang could be set free in return for an unnamed Iranian who has been detained in the US for nine months. Hua Qu, Mr Wang's wife, is a supporter of the Alliance. She said the comment put her in a difficult position. “That is an offer,” she said. “I want him to come back.”