Convicted Israeli spy Jonathan Pollard was rushed on Friday to a hospital several miles from FCI Butner in North Carolina, where he is incarcerated, following a “serious deterioration” in his condition.
It was reported on Friday that Pollard had very sharp pains, but the precise nature of the problem or its actual severity remains unknown.
Members of the Committee for Pollard said "there is a serious concern the present;; pains may represent a life-threatening crisis."
They also expressed hope that, should Pollard survive the current crisis, US President Barack Obama would grant clemency to Pollard so that he does not have to return to prison.
They say Pollard's poor condition, even if he survives the current crisis, would make a return to prison "a dangerous gamble with his life."
The Committee for Pollard established a situation room in the US in order to communicate with officials there.
Esther Pollard was deeply upset by the situation and was unavailable for comment.
Israel's Ashkenazi Chief Rabbi, Yonah Metzger reportedly called her to try to raise her spirits and reassure her.
Both Chief Rabbis are expected to meet with President Shimon Peres on Sunday to ask him to immediately ask for Pollard's release.
Peres, who asked for Pollard's release during his meeting with Obama in early March, is expected to do so again when the two presidents meet in June.
He will carry a letter signed by 80 Israeli lawmakers asking Obama to grant Pollard clemency.
Pollard, a civilian intelligence analyst for the US Navy, has been serving a life sentence since 1987 for one count of conspiracy to deliver national security information to a foreign government.
Pollard told Wolf Blitzer that year that he provided Israel with satellite photography of Palestine Liberation Organization (PLO) headquarters in Tunisia, specific capabilities of Libya's air defenses, and "the pick of U.S. intelligence about Arab and Islamic conventional and unconventional military activity."
Other's convicted of the same crime, including those who pass intelligence data to hostile nations, have been given average sentences of 7 years or less in prison.
Israel granted Pollard citizenship in 1995, but denies he was an Israeli agent. In 1998, Israeli officials said Pollard had worked for an "unauthorized rogue operation."
The disparity of Pollard's sentence with those of others convicted of the same crime has turned his lengthy incarceration into an issue for American Jewry.
Jewish and Israeli leaders have been joined by numerous US officials and lawmakers in calling for Pollard's release.