One of principal suspects in the 1998 East Africa embassy bombings, who was captured in Libya last year and taken to New York for prosecution, is terminally ill, raising questions about whether he can ever be put on trial, according to federal court documents.

Nazih Abdul-Hamed al-Ruqai, described by U.S. officials as a senior al-Qaeda planner, has been moved from a Manhattan detention center to North Carolina, where he is being treated.

U.S. Delta Force commandos and FBI agents captured the Libyan in early October in a raid outside his house in a suburb of Tripoli. Ruqai, also known as Anas al-Libi, was taken to a U.S. warship for interrogation but was moved to the United States days later because of health reasons.

At the time, U.S. officials said he was suffering from a hepatitis C but were apparently unaware of the more serious medical condition.

Bernard Kleinman, Ruqai’s attorney, declined to comment Friday. He said details of his client’s condition and treatment remain under seal.

Nazih Abdul-Hamed al-Ruqai, alleged al-Qaeda figure, moved to North Carolina for treatment. (Handout/Getty Images)

In recent interviews, members of Ruqai’s family raised the prospect that he has liver cancer. Medical experts say liver cancer is often a result of chronic hepatitis C.

Allan W. Wolkoff, chief of gastroenterology and liver diseases at Albert Einstein College of Medicine and Montefiore Medical Center in New York, said it is not uncommon for those with chronic hepatitis C to develop liver cancer.

“Of people with chronic hepatitis who reach the stage of cirrhosis, or scarring of the liver, they’re at high risk of development of liver cancer,” Wolkoff said. “Liver cancer is bad. It’s one of the cancers that generally appears late at an incurable stage. It’s pretty much a death sentence.”

The U.S. attorney’s office in Manhattan declined to comment.

Ruqai was scheduled to go on trial later this year in federal court in Manhattan on conspiracy to commit murder and other charges with two other men also accused in the bombing case: Khalid Al Fawwaz and Adel Abdel Bary. Fawwaz, a Saudi, and Bary, an Egyptian, were extradited from Britain in 2012.

Nearly simultaneous bombings outside the U.S. embassies in Dar es Salaam, Tanzania, and Nairobi, Kenya, in August 1998 killed 224 people, including 12 Americans. It was the first direct strike against the United States by al-Qaeda and came just months after Osama bin Laden called on Muslims to “kill the Americans and their allies.”

Attorneys for all three men have asked the judge to separate Ruqai from the case against other two defendants, and to try them separately. It’s not clear whether the judge, Lewis Kaplan, will move forward with the trial of all three as planned given Ruqai’s health.

As part of a severance motion, to be heard Wednesday in federal court in New York, a judge could make public Ruqai’s exact medical condition.

“Generally speaking, it is difficult to get a judge to sever a case,” said Mike Garcia, a former U.S. attorney for the Southern District of New York, where Ruqai is being tried.

Authorities moved Ruqai to a Federal Bureau of Prisons’ medical center in Butner, N.C., this year because of his medical condition, according to court records.

U.S. intelligence officials have said Ruqai had close ties to al-Qaeda and moved to Sudan in 1992 to work for bin Laden. While in Sudan, Ruqai was sent to Kenya to conduct surveillance on possible targets for an al-Qaeda operation, according to a federal indictment and former U.S intelligence officials.

Kleinman, Ruqai’s lawyer, says his client is innocent and had severed his ties with al-Qaeda before the 1998 attack. Kleinman has said his client never swore an oath of allegiance, or bayat, to bin Laden.

Ruqai lived in Iran for several years until the authorities in Tehran, without explanation, told him to leave.

He surfaced in Libya before the 2011 overthrow of Moammar Gaddafi. By mid-2012, the CIA knew that Ruqai was in Libya, U.S. officials have said.

Members of Ruqai’s family said they’re concerned that he might die before they can see him again. They said they are trying to obtain visas so they can enter the United States and visit him in the hospital.

Garcia, who was unaware of Ruqai’s health issues, said he expected that prosecutors would be pushing for a trial.

“If you’re a prosecutor and you’ve come this far, you want to see it through to a verdict,” he said. “There is also a benefit for the public to see the evidence against him. These are serious charges.”

He said it was unclear how the judge and the government will respond to the illness.

“As a prosecutor, I was skeptical of those claiming illness to avoid trial,” said Garcia, “but it will really depend on the judge’s assessment of the medical evidence and [his] fitness for trial.”

In August 2009, Abdel Basset Ali al-Megrahi, a Libyan who was found guilty of the 1988 bombing of a Pan Am flight over Lockerbie, Scotland, which killed 270 people, including 11 on the ground, was freed because he had prostate cancer.

Megrahi was released under a Scottish law that allows terminally ill prisoners to die at home. He was only expected to live three months after he returned to Libya, but he survived for almost three years before he died in May 2012.