U.S. Vice President Dick Cheney had directed his former top aide to leak classified material to discredit a critic of the Iraq war, The National Journal reported Friday.

Court papers released last week show that I. Lewis Libby was authorized to disclose the identity of a female CIA agent to media by "his superiors," in an effort to counteract her husband's charge that the Bush administration twisted intelligence on Iraq's nuclear weapons to justify the 2003 invasion, according to the report.

The National Journal, a U.S. weekly magazine, citing attorneys familiar with the matter, reported that Cheney was among those "superiors" referred to in a letter from prosecutor Patrick Fitzgerald to Libby's lawyers.

A lawyer for Cheney had no immediate comment.

Libby, Cheney's former chief of staff, faces perjury and other charges in the leak of the identity of Valerie Plame, a CIA agent who is the wife of war critic and former U.S. diplomat Joe Wilson, a move that effectively ended her career at the spy agency.

Libby has pleaded not guilty to five counts of perjury, making false statements and obstruction of justice.

Cheney's name has surfaced in other court documents as well.

According to an appeals-court decision made public last Friday, "the vice-president informed Libby 'in an off sort of curiosity sort of fashion'" that Wilson's wife worked at the CIA one month before her identity was made public.

Both documents cite testimony Libby made to a grand jury.

U.S. Senator Edward Kennedy, said Cheney's efforts to discredit Wilson could have risked national security.

"The Vice President's vindictiveness in defending the misguided war in Iraq is obvious. If he used classified information to defend it, he should be prepared to take full responsibility," Kennedy said in a statement.

The White House declined to comment on the issue.

Source: Xinhua