A human rights group says an Iranian-American art gallery manager and his wife have been detained in Iran, the latest in a series of arrests involving dual nationals in the Islamic Republic. The New York-based International Campaign for Human Rights in Iran said Friday that Karan Vafadari and his Iranian wife Afarin Niasari are being held in Tehran's Evin Prison. The group says no public charges have been brought and the couple has not had access to a lawyer since their arrest by the Revolutionary Guard in July. Iranian officials could not immediately be reached for comment. Iran does not recognize dual nationality. Several dual nationals arrested in recent years have faced secret charges in closed-door hearings, including Washington Post journalist Jason Rezaian, who was released in January. "Yet another case of a dual national snatched and held without charge or access to a lawyer represents an alarming continuation of a judicial system run by intelligence agencies with no respect for the law and no accountability," said Hadi Ghaemi, executive director of the human rights group. The statement said families of the arrested couple decided not to publicize their cases, hoping it would be resolved. "Then when the family started receiving anonymous phone threats and demands for money, they decided to go public and write a letter to Iran's supreme leader," the statement said. In the letter to Ayatollah Ali Khamenei, Vafadari's Washington-based sister Kateh said her sister-in-law was detained at Tehran airport as she was about to board a flight to attend a family wedding abroad, the statement said. "She was told to call her husband and ask him to come to the airport. When he arrived, he, too, was arrested and both were taken to Evin Prison." There was no immediate Iranian comment on the human rights group report. US State Department spokesman John Kirby said in a news briefing on Friday that US officials were aware of reports that a US citizen and US permanent resident had been detained in Iran, but he declined to comment further. — Reuters