Col Lawrence Wilkerson accused Mr Cheney of ignoring a decision by President Bush on the treatment of prisoners in the war on terror.

Asked by the BBC's Today if Mr Cheney could be accused of war crimes, he said: "It's an interesting question."

"Certainly it is a domestic crime to advocate terror," he added.

"And I would suspect, for whatever it's worth, it's an international crime as well."

This is an extraordinary attack by a man who until earlier in the year was Mr Cheney's colleague in the senior reaches of the Bush team, the BBC's Justin Webb in Washington says.

Col Wilkerson has in the past accused the vice-president of responsibility for the conditions which led to the abuse of prisoners.

But this time he has gone much further, appearing to suggest Mr Cheney should face war crimes charges, our correspondent adds.

Intelligence questions

He said that there were two sides of the debate within the Bush administration over the treatment of prisoners.

Mr Powell and more dovish members had argued for sticking to the Geneva conventions, which prohibit the torture of detainees.

Dick Cheney has been accused of advocating the use of terror

Meanwhile, the other side "essentially wanted to do away with all restrictions".

Mr Bush agreed a compromise, that "Geneva would in fact govern all but al-Qaeda and al-Qaeda look-alike detainees".

"What I'm saying is that, under the vice-president's protection, the secretary of defence [Donald Rumsfeld] moved out to do what they wanted in the first place, even though the president had made a decision that was clearly a compromise," Col Wilkerson said.

He said that he laid the blame on the issue of prisoner abuse and post-war planning for Iraq "pretty fairly and squarely" at Mr Cheney's feet.

"I look at the relationship between Mr Cheney and Mr Rumsfeld as being one that produced these two failures in particular, and I see that the president is not holding either of them accountable... so I have to lay some blame at his feet too," he went on.

In the BBC interview, Col Wilkerson also developed his views on whether or not pre-war intelligence was deliberately misused by the White House.

He said that he had previously thought only honest mistakes were made.

But recent revelations about doubts in the intelligence community that appear to have been suppressed in the run-up to the war have made him question this view.