Mr. Geithner responded calmly that he thought he had served the country “as carefully as I can” and would continue to do so as long as the president desired. But President Obama’s top economic officials have been dogged by complaints that they have been too quick to help the banking industry and not responsive enough to the plight of ordinary Americans who are suffering from high unemployment and a housing collapse.

The hearing on Wednesday was convened after the committee’s senior Republican member, Darrell Issa of California, obtained e-mail messages that suggested the Federal Reserve Bank of New York had prevented A.I.G. from revealing certain facts about the bailout in its filings with the Securities and Exchange Commission.

That made the possibility of a cover-up the latest flash point in the A.I.G. bailout drama. Previous points of contention have been the payment of sizable executive bonuses, and the fact that when the New York Fed first lent $85 billion to A.I.G., about $30 billion of it ultimately went to a group of big American and foreign banks.

Mr. Geithner, who was president of the Federal Reserve Bank of New York when the bailout began in September 2008, has been battered by Congressional panels over each issue, but has not gone off message. In a nutshell, he has maintained that the bailout was a tragic necessity, and that Congress should legislate financial reforms to prevent another one.

With respect to the e-mail messages about S.E.C. disclosure, at least, Mr. Geithner said he was the wrong person to consult. He was named President-elect Obama’s Treasury secretary in late November 2008, and had recused himself by the time those messages were sent.