I Lewis 'Scooter' Libby, who is chief of staff to Vice President Dick Cheney, was a source for a story surrounding the leaking of the name of a CIA operative.

The New York Times named Libby on Friday after he released the journalist from the confidentiality promised him. The journalist, Judith Miller, however had to spend the past twelve weeks in jail for refusing to disclose her source, before Libby stepped in.

Miller has now been released from jail and will testify before a grand jury on Friday morning.

The case has important implications for the Bush administration, the CIA, and the media. The story began when former Ambassador Joseph Wilson was sent by the CIA to Niger to investigate a document that had surfaced from foreign sources which alleged Saddam Hussein was seeking uranium enrichment for a nuclear bomb. The CIA had been requested to initiate an investigation on the instructions of Vice President Dick Cheney's office, after Cheney himself had raised the matter at a briefing.

Wilson subsequently visited Niger and reported back that the document could not be substantiated, nor could the allegation, which he declared was baseless. Despite Wilson's report, the claim was used by President Bush in his State of the Union address in January 2003 to bolster support for the invasion of Iraq.

Wilson subsequently went public to denounce the claim, and at the same time denouncing the war in Iraq.

Shortly after, Wilson's wife, Valerie Plame, was named by two journalists, Miller and Bob Cooper of Time magazine, as a CIA operative. Wilson alleged his wife's 'outing' was in retribution for his going public, and alleged the White House was behind it. The disclosure of a CIA agent's name is a Federal offence.

Karl Rove has already been named.