The Bush administration's response to corporate crime has been thrown into disarray by a series of resignations that has left both the Security and Exchange Commission (SEC) and a new accountancy oversight board without leadership.

Mr William Webster, head of the board, stepped down following disclosures that he had headed the audit committee of US Technologies, a company that is under investigation for fraud. This comes after the resignation last week of Mr Harvey Pitt, the head of the SEC, the main US regulatory body.

Mr Pitt knew of Mr Webster's link with US Technologies but did not tell members of the SEC board that appointed him last month. The accountancy oversight board was created earlier this year in the aftermath of a series of major corporate scandals that undermined confidence in US financial markets. Mr Webster, a 78-year-old former FBI director, said he believed his presence on the board would create "too many distractions". Another chairman cannot be appointed until the SEC has a new leader, which could take many months.

The debacle is an embarrassment for the White House, which appointed Mr Pitt to head the SEC last year and had also pressed for the appointment of Mr Webster. The controversy also brought about the resignation last week of the SEC's chief accountant, Mr Robert Herdman.