The White House spokesman is confirming that he's testified before a grand jury looking into the leak of a CIA officer's identity.
Scott McClellan says he cooperated fully with the panel last week, in keeping with President Bush's instructions.
Investigators are trying to find out who leaked the name of CIA undercover officer Valerie Plame to syndicated columnist Robert Novak in July.
She's the wife of a former ambassador who had said the Bush administration's claims about Iraq's nuclear weapons ability were exaggerated.
Whoever leaked the name could be charged with a felony.