A US appeals court has ruled that two reporters must testify about their sources in an investigation into the leaking of a CIA officer's name.
The jury is probing any link between the leak and the White House
The three-judge panel ruled that New York Times reporter Judith Miller and Matthew Cooper of Time Magazine must appear before a federal grand jury.
The move is part of an investigation into whether officials leaked the agent's identity to the media.
The decision upholds a ruling that the pair were in contempt of court.
Miller and Cooper each could face as much as 18 months in prison if they continue to refuse to testify.
"There is no First Amendment privilege protecting the evidence sought," Judge David Sentelle wrote in his decision.
Previously, US District Judge Thomas F Hogan had ruled that Cooper must testify "regarding alleged conversations they had with a specified executive branch official".
Miller gathered material for a story but never wrote one.
Investigators are investigating claims that government officials were involved in the leak to the media of the name of CIA agent Valerie Plame.
She was named in a piece by journalist Robert Novak
Ms Plame's husband, former diplomat Joseph Wilson, says her name was leaked in retribution for an article he wrote challenging the government over Iraq.
Mr Wilson, a former US charge d'affaires in Baghdad, was sent by the CIA to Niger to investigate claims that then Iraqi leader Saddam Hussein had tried to obtain uranium for nuclear weapons.
He concluded that there was no evidence, but Mr Bush still referred to the claims in his 2003 State of the Union address.
A week after Mr Wilson's article appeared questioning the policy on the Niger allegations, Ms Plame was exposed by journalist Robert Novak - who based his report on two unidentified senior administration officials.
Disclosing a covert agent's name is a criminal offence in the US, punishable by up to 10 years in prison.