The US Congress will conduct a series of hearings on national security and espionage issues raised by the CIA-leak controversy surrounding President George W. Bush's senior adviser, Karl Rove.
The House Permanent Select Committee on Intelligence plans hearings on potential national security threats posed by leaks, including leaks to the media, and will aim to toughen legislation barring the unauthorised disclosure of classified information.
"It's time there's a comprehensive law that will make it easier for the government to prosecute wrongdoers and increase the penalties that hopefully will act as a deterrent," said Republican Pete Hoekstra of Michigan, the panel's chairman.
Media leaks and the covert status of espionage officials have become politically charged issues with the controversy over Valerie Plame, whose identity as a CIA agent was leaked in 2003 after her diplomat husband Joseph Wilson accused the White House of exaggerating intelligence to justify the Iraq war.
A Timemagazine reporter said he learned about Ms Plame's identity from Mr Rove, deputy White House chief of staff and chief architect of President Bush's re-election.
Timereporter Matthew Cooper also said he discussed Ms Plame and Mr Wilson with Lewis "Scooter" Libby, Vice President Dick Cheney's chief of staff.
New York Timesreporter Judith Miller was jailed for refusing to disclose the source who revealed Ms Plame's identity to her despite her not publishing the name.
It can be illegal for a government official to knowingly disclose the identity of a covert CIA operative.
Democrats, who have urged President Bush to fire Mr Rove or revoke his classified clearance, stepped up political pressure on Republicans by calling for a formal congressional investigation of the Plame leak.