Navy Cmdr. Andrea Lockhart disclosed the magazine had turned up at Guantanamo during a pre-trial hearing Wednesday for alleged al-Qaida leader Abd al-Rahim al-Nashiri, who allegedly masterminded the 2000 USS Cole bombing, which killed 17 American sailors, ABC News reported.
Lockhart didn't say the magazine was al-Nashiri's and didn't say where it came from or what issue it was.
The disclosure came as Lockhart discussed a system used by civilian lawyers to send materials to Guantanamo captives suing the United States for their freedom through habeas corpus petitions in Washington, The Miami Herald reported.
Lockhart defended the prison camp commander's plan to more closely scrutinize legal mail for alleged terrorists.
Army Col. James Pohl, the chief military commissions judge, gave defense lawyers for al-Nashiri a week to submit a proposed legal mail control order.
The Herald said Pentagon and prison officials did not say which edition of the magazine got inside the camps nor whether a captive had seen it or how it was discovered.
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