But he said Khan walked away from the group when it was clear his fellow officers were not interested in joining. The colleague said that he himself had also been approached by Hizb ut-Tahrir, via a cousin, but had turned them down.
"Our brother is honest and outspoken," said Khan's younger brother Bashir Ahmed. "He may have spoken against higher authorities and they don't like people to speak that way. That's why they are holding him."
At a meeting with other officers days after the May 2, 2011, raid by U.S. commandos that killed Osama bin Laden, Khan spoke out against the operation, which he and others on the forces considered a national humiliation.
Khan was arrested on May 5 and his manifesto presents himself as a "victim" of the bin Laden raid.
His lawyer, Rahiem, sought to submit the tract to a government commission investigating the bin Laden incident, but it was rejected. Some of the passages were included in a letter he sent to Gen. Kayani some time before his arrest, Rahiem said.
The manifesto doesn't call for an armed insurrection, support Islamic militancy or mention Hizb ut-Tahrir.
Rather, it is a refutation of Pakistan army's alliance with Washington, along the lines of what is often espoused by right-wing, Islamist Pakistanis. It buttresses its arguments with conspiracy theories, including that the United States was behind the Sept. 11, 2001, attacks. In Afghanistan, he recommends a U.N. force of mostly Muslim nations to replace the current U.S.-led one.
Image: A Pakistani Shiite Muslim protestors steps on representations of US and Israeli flags, during an anti-Israel rally and in solidarity with the Palestinian people, in Karachi, Pakistan, Sunday, May 13, 2012.