Faced with an investigation ordered by the Treasury Department, O'Neill said the documents he had shown on television while criticising Bush for the war on Iraq, were given to him by the Treasury's chief legal officer after he requested them to help a journalist write a book.
"I said to the general counsel I would like to have the documents that are OK for me to have. About three weeks later, the general counsel, the chief legal officer, sent me a couple of CDs, which I frankly never opened," O'Neill said.
O'Neill, ousted last year from Bush's economic team, was responding to a formal investigation launched into how a document marked "secret" was shown during his television interview, coinciding with the launch of a book on his experiences in the administration.
O'Neill stirred a hornet's nest with his interview, accusing Bush of plotting the war against Iraq from the very early start of his presidential term.
Meanwhile, smarting under O'Neill's damning disclosure, the administration is working overtime to downplay his comments.
Defence Secretary Donald Rumsfeld said he called O'Neill twice about the book, but did not ask him to refrain from writing it.
In the book, The Price of Loyalty, Bush is depicted as a bullying, passive and superficial president, surrounded by right-wing ideologues.