Billionaire investor Warren Buffett has long been revered in the business world, but his importance at a trial involving the world's largest insurer is hotly contested.

Jurors at the fraud trial of four former General Reinsurance Corp. executives can hear a taped conversation in which a witness said American International Group Inc. will "find ways to cook the books," a U.S. judge ruled.

The House Judiciary Committee wants to know why the Justice Department abruptly dropped a federal criminal probe into allegations of insurance fraud at Berkshire Hathaway's General Reinsurance (Gen Re) unit.