Billionaire investor Warren Buffett is expected to testify in the case of insurance giant American International Group, joining the company’s ousted CEO and chairman Maurice ``Hank’’ Greenberg, according to the WSJ.

Buffett’s holding company Berkshire Hathaway owns insurance firm General Re that is cooperating with the probe launched by the Securities and Exchange Commission and New York State Attorney General Eliot Spitzer.
The interview, aimed at revealing extra facts in the accounting scandal around AIG, will be held without a court reporter to record Buffett’s testimony which will be given by him without an oath. The objective of the interview is in General Re’s transactions with AIG some five years ago that lead to highly improved figures for the world’s No.1 insurer.

AIG has already restated earnings downward by $1.7 billion under the probe. "These are very serious offenses, over a billion dollars of accounting frauds that AIG has already acknowledged," Mr. Spitzer said.

The company agreed to help investigators and has already fired some of its top executives that invoked their Fifth Amendment rights to avoid testifying to government investigators.

Greenberg was forced to step down as the company’s CEO and later chairman after he refused to cooperate with the investigation. "That company was a black box, run with an iron fist by a CEO who did not tell the public the truth. That is the problem," said Mr. Spitzer.