The Wall Street Journal reports Rumsfeld approved the tactics in December 2002. When military lawyers complained about the tactics being used, officials re-examined the techniques and implemented new rules in an April 2003 memo.
It is not known what tactics were approved in the April 2003 memo, but a March 2003 draft of that memo — revealed earlier this week — contained a legal argument that neither President Bush, nor agents acting on his orders, could be held liable for violating anti-torture laws in the war on terrorism.
USA Today reports that lawyers for Joint Chiefs of Staff Chairman Gen. Richard Myers were worried that tactics included in the April 2003 memo could make the chairman a target for prosecution under laws governing prisoner treatment.
The focus on the memos comes amid the continuing investigation of possible prisoner abuse. After photographs surfaced showing abuse at Baghdad's Abu Ghraib prison, details have emerged about deaths in custody in Afghanistan and the reported use of interrogation tactics like near-drowning at Guantanamo Bay.
It is not known if the tactics Rumsfeld approved for Guantanamo Bay were used at Abu Ghraib, where some of the alleged abuse involved dogs.
The commander of Guantanamo Bay, Maj. Gen. Geoffrey Miller, recommended in the summer of 2003 that military police guards at Abu Ghraib "set the conditions" for the interrogation of prisoners, a recommendation that other Army officers have said was inappropriate.
The prison abuse probe turns on whether the mistreatment was the act of individual soldiers or the result of policies ordered higher up the chain of command.
In other developments:
Some Democrats in Congress have said the 2002 and 2003 memos from Justice Department and Pentagon lawyers suggest the Bush administration was constructing a legal defense for torture.
Waving photos of abused prisoners in Iraq, Sen. Edward M. Kennedy, D-Mass., said such memos could lead to interpretations by military personnel or interrogators that laws and agreements that forbid torture were no longer in effect.
"We know when we have these kinds of orders what happens: We get the stress test, we get the use of dogs, we get the forced nakedness that we've all seen, and we get the hooding," Kennedy said.
Attorney General John Ashcroft, in a letter Tuesday to Sen. Patrick Leahy of Vermont, denied that the Justice Department was condoning torture. But the attorney general refused to give the committee copies of the memos.
"I do believe the president has the right to have legal advice from his attorney general and not have that revealed to the whole world," said Ashcroft.
Sen. John Kyl, R-Ariz., said terrorists could train to resist certain interrogation techniques if documents detailing them were made public.
Bush administration officials say the memos were aimed mainly at showing that international treaties banning torture do not apply to al Qaeda and Taliban prisoners.
The department's lawyers concluded that Taliban and al Qaeda fighters are not protected by the Geneva Conventions because they do not satisfy main conditions of the treaty itself, like wearing uniforms.
William Moschella, assistant attorney general for legislative affairs, said in a letter released Wednesday that despite this important difference, President Bush early in the Afghanistan conflict issued orders that al Qaeda and Taliban prisoners be treated humanely and consistently with Geneva Conventions principles.
Iraqi prisoners are protected under the treaty partly because Iraq is a participating nation in the Geneva Conventions and the United States is an occupying power, Ashcroft wrote.
A Pentagon spokesman tells the Journal that the tactics approved by Rumsfeld in Dec. 2002 were a reaction to intelligence suggesting an attack was imminent. Interrogators proposed 20 tactics, Rumsfeld approved 17 of them, and 10 were actually used, but only on one detainee suspected of involvement in the Sept. 11 plot.
USA Today reports that in the subsequent April 2003 memo, Rumsfeld approved 24 methods, including four not usually used by military interrogators.