Ayaz Ahmed was arrested in June by U.S. Immigration and Customs Enforcement because he had an expired visa, according to his lawyer, Hashim Siddique. Ahmed had no criminal record, Siddique said. His family hired the attorney to speed up his removal, fearing his health would decline in detention.

Ahmed required a breathing device, nasal spray and medication for chronic conditions, including high blood pressure and a possible heart condition, Siddique said. Before the July flight to Pakistan, he was held at the Clay County Detention Center in Indiana.

Around June 10, Siddique contacted the jail after Ahmed's family raised concerns about whether he was receiving his prescribed medication. A jail officer assured him that Ahmed was getting the drugs, the attorney said. Siddique also spoke with Ahmed, who said he was receiving medication at that time but could not confirm whether it was being provided consistently.

"He may have been [receiving his medication] when I spoke to him, but I don't know if he was receiving it daily," Siddique said. "That I don't know."

Siddique said he notified ICE of Ahmed's medical needs and was told the concerns would be forwarded to the detention center. Clay County officials repeatedly told him that detainees could request care through electronic tablets, but Ahmed was not fluent in English, and Siddique questioned whether he could use the system properly.

On June 18, Siddique learned that Ahmed had been placed in medical isolation. A Clay County officer cited claustrophobia, he said, but the circumstances remain unclear. Siddique described medical isolation as similar to solitary confinement, with Ahmed alone in a cell.

Clay County officials confirmed that Ahmed was held there but would not answer questions about his medical care.

In the days before his removal, Ahmed was transferred through several facilities, according to Siddique. On July 24 he was moved to Jackson Parish Correctional Center in Louisiana; three days later he was sent to Camp East Montana in El Paso, Texas; and on July 29 to Prairieland Detention Center in Alvarado, Texas.

Siddique said he does not know whether Ahmed received his prescribed medication at each facility or during the deportation flight.

"He keeps getting transferred, and then I'm not sure if everything went with him," Siddique said.

Alexa Van Brunt, director of the Illinois office of the MacArthur Justice Center, is part of a legal team that recently filed a class-action lawsuit challenging conditions at the Miami Correctional Facility, an Indiana prison that also holds ICE detainees. The suit alleges inadequate medical care, delays in receiving prescribed medications, prolonged solitary confinement and unsanitary conditions.

Van Brunt said frequent transfers between detention facilities pose another risk for people with chronic illnesses.

"That's another impediment to proper care because there's no continuity of care for people with chronic diseases like cancer or diabetes," she said.

ICE said Ahmed was medically cleared for travel and was no longer in its custody when he died.

"No medical emergencies occurred during the flight, no signs of medical distress were observed, and no individuals required hospitalization upon landing," the agency said in a statement. ICE said Ahmed received all his scheduled medication during the flight and called any claims of neglect or mistreatment "categorically FALSE."

But after the plane landed, Ahmed collapsed on the tarmac in Pakistan, according to Siddique. The attorney said Ahmed's son emailed him saying his father died seven hours after landing in Islamabad.

ICE said that once Ahmed was transferred to the custody of the Pakistani government, the agency no longer had "authority over their care or access to their medical or official records."

Ahmed's family is exploring legal action, Siddique said.

Some Chicago advocates are calling for an independent criminal investigation into Ahmed's death and ICE's medical standards.

"This heartbreaking and entirely preventable tragedy lays bare the harrowing human cost of rushed, aggressive immigration enforcement," Ahmed Rehab, executive director of CAIR-Chicago, said in a statement.

The Pakistan Consulate in Chicago and the Pakistani Embassy did not respond to requests for comment.