The photos have been circulating on jihadist Web forums, along with pictures of his nephew, Ammar Al Baluchi.
The pictures, taken by representatives of the International Committee of the Red Cross, have been posted on pro-al Qaeda Internet Web forums for the past several days, and were posted Wednesday by Jarret Brachman, a consultant to the U.S. government on counterterrorism and author of "Global Jihadism."
Brachman said he found the pictures on the Internet with a colleague he described as a cybersleuth. The pictures were posted on Brachman's blog, jarretbrachman.net. In the pictures Mohammed is wearing flowing white robes, and in one he shows a thin smile. An official with the Red Cross confirmed to ABC News that the pictures were taken by Red Cross members in July and sent to family members of the detainees.
The Red Cross, as part of its Red Cross Messages program, has allowed Guantanamo Bay detainees to receive letters from their family members. In February, detainees were allowed to send pictures to their family members under the program. According to Red Cross spokesman Bernard Barrett, U.S. authorities review the pictures and mail messages before they are sent to family members for any sensitive information.
It is believed that the pictures were sent by Mohammed's family members to pro-al Qaeda Web sites.
Brachman told ABC News in an interview that he debated whether to post the pictures on his blog with the 9/11 anniversary approaching. No pictures of the 9/11 mastermind had been seen since he was captured in March 2003 in Pakistan and moved in to the CIA's High Value Detainee Program.
Mohammed had only been seen and sketched by courtroom artists in military commission proceedings at Guantanamo Bay. The release of the pictures comes as the Obama administration is deciding how to close the Guantanamo Bay facility with U.S. prosecutors reviewing evidence to determine if they will try Mohammed in a federal court or move forward with revamped military commissions.
Brachman said that al Qaeda propaganda usually did not make reference to Mohammed but that these pictures on pro-al Qaeda Web forums could lead to that.
"Al Qaeda had thrown KSM under the bus." Brachman said. "This is a new wave of support. ...This is remembering who he is."
Mohammed's nephew, Ammar al-Baluchi, is seen in one picture (below) holding a book believed to be the Koran.
Al-Baluchi was also detained in the CIA secret prisons. Officials say he was a key aide for his uncle.