At least two of the suspects in the 9/11 terror attacks have been on hunger strikes at the Guantanamo Bay detention camps since January, Fox News has learned.

The men, among the so-called “high value 14” who were transferred from the CIA secret prisons in 2006 to the Navy base in Cuba, are protesting conditions at Guantanamo’s Camp 7 and a new policy in which communications between detainees and their defense lawyers are reviewed for security purposes, according to knowledgeable sources who would not provide further detail.

It is not clear whether the men are refusing all foods and fluids or whether they are eating only on an occasional basis.

Defense Department spokesman Todd Breasseale said he could not discuss health-related issues of the 9/11 suspects, adding, “the physical well-being of detainees is our primary responsibility, and their security is of vital importance to our mission there. ... Hunger strikes are a form of non-violent protest, and those few who have engaged in this practice are monitored so that their health is never in any real danger. Their vital statistics are routinely monitored and they are not allowed to endanger their lives.”

In December, the admiral who oversees the detention camps ramped up the screening of communications and mail between the lawyers and their clients to keep out contraband. In January, it came to light during a routine military hearing at the base, that a copy of Al Qaeda’s Inspire magazine, likened to the “Martha Stewart Living” for would-be jihadists, nearly made it into the camps.

The American Bar Association has written to Defense Secretary Leon Panetta about the preservation of attorney-client privilege in the Guantanamo military prosecutions. While urging Panetta to take immediate steps to “rescind this policy,” Bill Robinson III, president of the ABA, wrote that it was especially important in death penalty cases.

The Defense Department’s current policy, Robinson said, "seriously compromises the ability of lawyers to meet their obligations and provide ethically and constitutionally adequate representation to their clients. It also impairs the ability of these dedicated lawyers to gain the trust and confidence of their clients.”

As for conditions at Camp 7, a detention facility so secretive that no journalist has ever been given access, it is claimed that they do not satisfy the requirements under the Geneva Conventions that establishes minimum guarantees for the treatment of “law of war detainees.”

On Feb. 24, all of the military defense lawyers for the 9/11 suspects at Camp 7, along with the lawyer Abu Faraj al-Libi, a Libyan implicated in a plot to blow up planes over the Atlantic in 2006, wrote to William K. Lietzau, deputy assistant secretary of defense for detainee policy. They claimed in the five-page letter that serious deficiencies remain in health care and living conditions.

The lawyers questioned the validity of a 2009 declassified report that stated the detainees enjoyed recreation yards with “elliptical machines and stationary bikes, soccer balls, racquetballs ... media rooms are available three times weekly for each detainee to watch movies of their choice, read newspapers, magazines (and) books.”

The lawyers said they “are not in a position to speculate as to the reason for the changes. ... Nonetheless, some appear to coincide with the arrival of the current JTF-GTMO commander, who has publicly expressed that he lost two comrades in the 9/11 attacks, and that he defines himself as part of the “9/11 generation.”

Fox News chief intelligence correspondent Catherine Herridge's bestselling book "The Next Wave: On the Hunt for al Qaeda's American Recruits" draws on her reporting for Fox News into Anwar al-Awlaki and his new generation of recruits -- al Qaeda 2.0. It also investigates the Obama’s administration’s claims of transparency at the Guantanamo Detention camps.