US Secretary of State Hillary Clinton has referred to former Vice President Dick Cheney as an "unreliable source of information."

Appearing in front of the House Foreign Affairs Committee, she has spoken about President Obama's decision to consider the possible prosecution of former Bush administration officials involved in formulating legal justifications for harsh interrogation methods on suspected terrorists.

While, President Obama has said he would not favour prosecution of CIA agents and others who conducted the interrogations, Ms Clinton reiterated the administration’s stance that possible Justice Department action could be brought to bear against former high officials who sanctioned interrogation methods such as "waterboarding."

Former Vice President Cheney has asked for the declassification of CIA documents to support his assertions that harsh interrogation techniques used on some terror suspects had yielded valuable intelligence.

Testifying before the House Foreign Affairs Committee on Wednesday, Ms Clinton exchanged her views with California Republican Dana Rohrabacher, who asked if the Secretary of State would be agreeable to former Vice President Cheney's effort to force the release of classified documents.

Rohrabacher: "Are you in favour of releasing the documents that Dick Cheney has been requesting be released?"

Clinton: "Well, it will not surprise you that I do not consider him a particularly reliable source of information."

Rohrabacher: "Madame Secretary, I asked you a specific question. Dick Cheney has asked for specific documents to be unclassified, we are not asking your opinion about Dick Cheney.

Clinton: "Well, Congressman I believe that we ought to get to the bottom of this entire matter. I think it is in the best interests of our country and that is what the president believes and that is why he has taken the actions he did."