Andersen auditors learned of the commission's inquiry that same week.

Now the disclosure of the document destruction raises the possibility that some Andersen auditors knew more than they wanted investigators to realize they knew.

In all three cases, Andersen auditors spotted bad accounting but were persuaded it was immaterial and therefore allowed it to go ahead.

All of Waste Management's top financial officials were former Andersen auditors.

"Andersen auditors would never, under any circumstances, tolerate an arrangement intended to manage earnings," he said.

If it turns out that Andersen auditors destroyed actual work papers, many accounting experts would be shocked.

"None of these things happen overnight," the executive said, adding that groups of Andersen auditors in other offices were also exploring possible transactions.

Some of the remaining Final Four accounting firms are getting new clients now by agreeing to hire the Andersen auditors who previously did the work.

Andersen auditors "do not appear to have followed generally accepted auditing standards," he wrote.

Testimony by an Andersen auditor has bolstered prosecutors' contentions that managers ordered the shredding of documents.