Karl Rove, US President George Bush’s chief political adviser, will step down if indicted in connection with the leaked identity of a CIA agent, it has been claimed.

He would resign or take unpaid leave if accused of a crime by a grand jury, according to Time magazine.

Special Counsel Patrick Fitzgerald is investigating whether anyone in the Bush administration broke the law by revealing the identity of covert CIA operative Valerie Plame.

Judith Miller, a New York Times journalist, spent three months in jail for refusing to reveal her sources in connection with the story that has caused a furore in the US.

She eventually agreed to testify last month, naming Vice President Dick Cheney’s chief of staff Lewis “Scooter” Libby as a contact.

Rove became embroiled in the scandal after discussing the matter with Time magazine reporter Matt Cooper.

He and Libby are two of the most powerful political players in Washington.

Time magazine said resignation was the most likely scenario if either man is indicted, citing several legal and political sources.

Rove could be charged with perjury for failing to testify that he had spoken to Cooper about Plame, despite later correcting himself.

A former White House official said Rove’s break with Bush would have to be clean, with no “giving advice from the sidelines” for the sake of the administration.

Plame was an expert on weapons of mass destruction whose husband, Joseph Wilson, is a former ambassador who questioned President George Bush’s claims that Saddam Hussein’s regime was trying to buy uranium in Africa.

Her identity was first revealed by syndicated columnist Robert Novak on July 14, 2003.

No charges have been filed. The grand jury ends its investigation on October 28.