FBI probing bailout firms Investigators start search for fraud at Fannie Mae, Freddie Mac, Lehman WASHINGTON (AP) -- The FBI is investigating four major U.S. financial institutions whose collapse helped trigger a $700 billion bailout plan by the Bush administration. Two law enforcement officials said Tuesday the FBI is looking at potential fraud by mortgage finance giants Fannie Mae (FNM, Fortune 500) and Freddie Mac (FRE, Fortune 500), Lehman Brothers Holdings Inc. (LEH, Fortune 500), and insurer American International Group Inc. (AIG, Fortune 500) The inquiries, still in preliminary stages, will focus on the financial institutions and the individuals that ran them, a senior law enforcement official said. Officials said the new inquiries brings the number of corporate lenders under investigation over the last year to 26. Spokesmen for AIG, Fannie Mae and Freddie Mac did not immediately return calls for comment Tuesday evening. A Lehman spokesman did not have an immediate comment. The law enforcement officials spoke on condition of anonymity because the investigations are ongoing and are in the very early stages. Just last week, FBI Director Robert Mueller put the number of large financial firms under investigation at 24. He did not name any of the companies under investigation but said the FBI also is looking at whether any of them have misrepresented their assets.