The family of Ryan Corbett, an American humanitarian who has been imprisoned without charge by Afghanistan’s Taliban rulers since August 2022, said a brief, “disturbing” phone call from him this week has them increasingly concerned about his declining mental and physical health.

Anna Corbett, Ryan’s wife, said in a statement that she and their three children received a “deeply disturbing 12-minute call from Ryan” on Tuesday, “in which Ryan exhibited a significantly deteriorated mental state. His captors have told him that he is forgotten by his country, and it seems he now believes them.”

The family, who live in New York, said Ryan told them on the call that he’d suffered from “high fevers last week that went undiagnosed.” 

Anna and the couple’s three children, 18-year-old Ketsia, 16-year-old Miriam and 13-year-old Caleb, have had just five short phone calls from Ryan, totalling 44 minutes, since he was detained in Afghanistan by the Taliban in August 2022, a year after the Islamic extremists retook control over the country and the U.S.-led international military coalition withdrew. 

Taliban intelligence officials told CBS News in December that Ryan, 40, was accused of anti-state activities, a common accusation made against Westerners. Corbett has been determined to be “wrongfully detained” by the U.S. State Department, indicating the government’s assessment that the charges against him are baseless.

“I’m really scared,” Anna told CBS News on Wednesday. “Something could happen to Ryan and nobody would even know. He’s often isolated for long periods of time, and with reports of seizures, fainting, discolored extremities and now deep despair, I worry every day that he may not make it home alive.” 

“I want the president to realize that the lack of action to bring Ryan home could have disastrous consequences,” she added, referring to President Biden.

Qatar, which acts as the United States’ Protecting Power for Afghanistan in lieu of formal diplomatic relations between Washington and Kabul, has sent officials to visit Ryan in person twice, first in January 2023, and again in December. 

In an exclusive TV interview in December, Anna told CBS News that Ryan had been suffering from a constant ringing in his ears and deteriorating vision, as well as seizures during his imprisonment by the Islamist militants almost 600 days ago. She also said a childhood accident had left Ryan with a collapsed lung, making him more prone to pneumonia while being held “in a damp and cold basement” since his imprisonment. 

A Taliban intelligence official told CBS News in December that Ryan’s health was “fine,” that he was being held in a “guesthouse” with daily access to sunlight, goat and sheep meat, newspapers, magazines and a small gym. CBS News has not verified those claims. 

Suhail Shaheen, the Taliban’s appointed envoy to the United Nations, also told CBS News: “We don’t torture or mistreat anyone in custody.”

A State Department spokesperson told CBS News the government was aware of Ryan’s latest phone call to his family and was “concerned about the well-being of Americans detained in Afghanistan and actively working for their release.”

“U.S. officials have continuously pressed, including in meetings with Taliban representatives, for the immediate and unconditional release of Americans detained in Afghanistan, noting that these detentions are a significant obstacle to positive engagement,” the spokesperson said, adding that “for privacy, safety, and operational reasons, we won’t speak publicly to their cases.”

Margaret Brennan and Olivia Gazis contributed to this report.