WASHINGTON (Bloomberg) - The Federal Bureau of Investigation (FBI) is investigating 14 corporations for possible accounting fraud and other crimes related to the sub-prime lending crisis, officials said.

Neil Power, chief of the FBI's economic crimes unit, would not identify the companies, though he said the cases involve "valuation-type stuff." The probes include reviews of subprime lenders, housing developers and Wall Street banks that package loans as securities, he said.

"We're looking at the accounting fraud that goes through the securitisation of these loans," Mr. Power said at a briefing with reporters in Washington yesterday. "We're dealing with the people who securitise them and then the people who hold them, such as the investment banks."

The probes add to federal and state scrutiny of the home- loan industry as prosecutors and regulators seek to assign culpability for the mortgage rout that has forced people from their homes and resulted in losses to investors. The biggest banks and securities firms have posted at least $133 billion in credit losses and writedowns related to the loans, which are typically made to buyers with the weakest credit.

The Securities and Exchange Commission, which brings civil cases, has about three dozen inquiries open, the agency's deputy enforcement director said earlier this month.

The FBI works "hand-in-hand" with the SEC, Mr. Power said yesterday.

On sub-prime lenders, Power said the bureau has been "looking over their books and of course there are some irregularities there that we're looking into."

Mr. Power said another area of criminal inquiry is insider trading - whether executives sold shares when they knew loan defaults were going to surge.