01 Sep.

The US Financial Crisis Inquiry Commission, is expected to report to the nation by Dec. 15 on the causes of the 2008 financial debacle. It is investigating 22 factors, including Asian savings, regulatory failings in the United States, executive pay and credit ratings.

The commission hopes to produce a detailed report that will influence future policy making. It has held 12 days of hearings, interviewed more than 500 witnesses and pored over hundreds of thousands of pages of documents.

But as the commission prepares for its final round of public hearings on Capitol Hill this week — including appearances by Richard S. Fuld Jr., the former chief executive of Lehman Brothers, on Wednesday, and Ben S. Bernanke, the chairman of the Federal Reserve, on Thursday — it faces substantial obstacles.

In May, the commission’s executive director was moved aside and succeeded by an economist from the Fed, a decision that drew criticism since the central bank is an object of the investigation because of its leading role in handling the crisis. In addition, five of the commission’s 14 senior staff members have resigned, including Matt Cooper, a journalist who was drafting the report.

Moreover, the commission’s chairman, Phil Angelides, and vice chairman, Bill Thomas, are finding it challenging to maintain support from all eight other commissioners. While squabbling within the panel has not broken into open dissent, several commissioners are divided over how much to blame specific individuals and banks, how and when to release the documents it has gathered and whether to make available testimony of government officials and bank executives it has interviewed privately.

Thomas said that the law establishing the commission did not mandate unanimity, but “it’s always desirable,” he said.