NEW YORK: The growing sense of crisis within the Bush administration over the aftermath of the Iraq conflict deepened on Saturday after it emerged that Vice-President Dick Cheney has been questioned as part of the intelligence scandals engulfing American politics.

He has been interviewed as part of a probe into the leaking last year of the identity of undercover CIA agent Valerie Plame, wife of ex-diplomat Joe Wilson, a vocal critic of the administration in the build-up to the Iraq war, especially claims about Saddam Hussein's weapons of mass destruction.

News of Cheney's grilling follows the resignation of CIA chief George Tenet and will add to the pressure on a Republican party already sinking in the polls. George Bush's approval ratings are at an all-time low of 42 per cent, dangerously close to the 40 per cent level seen as the point beneath which victory is unlikely.

Cheney, a hate figure for liberals due to his corporate contacts in the defence industry, was questioned about his knowledge of anyone on his staff who may have leaked Plame's name. It is not believed that Cheney himself is the suspect in the leak, a federal crime that carries the risk of a jail sentence.

However, intelligence sources have pinpointed the leak as coming from Cheney's office. His chief of staff, Lewis 'Scooter' Libby, has been named in several press reports as a possible suspect.

It is also believed that the investigation has pulled phone records from Air Force One as part of their probe. Observers think that Plame's identity was deliberately leaked to conservative newspaper columnist Bob Novak as a way of punishing her husband. "It came out of Cheney's office. These are a very serious group of people," said Mel Goodman, a former top CIA officer.

The case is reaching high into the halls of power. Bush himself last week consulted a private lawyer, Jim Sharp, in case he is questioned. In a worrying echo of previous scandals, Sharp once worked as counsel in the Iran-Contra hearings during the 1980s scandal that almost wrecked Ronald Reagan's presidency.

The probe is now the hot talk of Washington's corridors of power amid intense speculation that charges will be brought. "If they can get the proof, someone will pay for it," said Larry Johnson, a former CIA agent and senior counter-terrorism official at the State Department.

The case is just one of several intelligence scandals. The Pentagon is being probed over the activities of Ahmed Chalabi, who helped to provide much of the information used as a basis for invading Iraq.

He is now thought to have passed secrets to Iran, including news that the US had broken Iranian intelligence codes. FBI investigators have used lie-detector tests on Pentagon officials to determine who passed secrets to Chalabi.

Two other investigation reports, one from the 9/11 Commission and another from the Senate, are also due in the next month and are expected to slam US intelligence-gathering in Iraq.

As negative news swamped the Bush campaign, his Democratic opponent, John Kerry, has kept a low profile. Democrat strategists believe news events alone are derailing Bush and recent poll numbers have added to the sense of Republican crisis. One survey showed almost 20 per cent of Republicans were considering not voting for Bush.

"That is a very serious problem," said John Zogby, head of polling firm Zogby International. One of America's most respected pollsters, Zogby believes Bush's numbers are so bad that the election has become Kerry's to lose. -Dawn/The Observer News Service.