The FBI is investigating whether criminal wrongdoing contributed to the collapse of IndyMac, a large mortgage lender that failed Friday.
FBI agents who specialize in white-collar crime have been investigating IndyMac for at least a month, said a Justice Department official who couldn't be named because the department doesn't comment on investigations.
The investigation includes a look into the bank's financial practices involving mortgages, the official said.
The FDIC took control of IndyMac, of Pasadena, Calif., after customers had withdrawn $1.3 billion in 11 business days. IndyMac, with $32 billion in assets, was the fourth-largest financial institution ever to fail, based on inflation-adjusted assets.
The FBI says in a statement the agency doesn't "confirm or comment about specific companies that may or may not be a part of our investigations."
It says it is conducting 21 probes related to the subprime market, up from 19 in April. "Given the volatility of today's subprime market, we have seen an increase in subprime related complaints," the statement says.
FDIC spokesman Andrew Gray declined to comment.
Companies charged with criminal wrongdoing could face fines or have to pay restitution. If the FBI finds evidence that the company or its officers broke the law, it would present the case to a U.S. attorney, who would decide whether to pursue criminal charges.
Former IndyMac CEO Michael Perry said Wednesday that the FBI had not contacted him. He declined to comment further.
As the housing market has collapsed, federal regulators and Congress have considered reform to mortgage-lending practices. The FBI has launched criminal investigations of mortgage lenders, investment banks and other financial services companies. The investigations, according to the agency, focus on inside trading and accounting and loan fraud, among other areas.
In June, two former Bear Stearns hedge fund managers became the first on Wall Street to be hit with criminal charges stemming from the mortgage mess. The managers were indicted on securities fraud charges for allegedly lying to investors about the health of mortgage-backed bonds held in their hedge funds.