A probe in sub-prime accounting has been launched by the Federal Bureau of Investigation.

The Wall Street Journal reports that the FBI is investigating 14 companies and will concentrate on how the loans were securitised and how companies packed sub-prime mortgages into the stacks of debt the banks held as assets. The FBI would not name the companies investigated.

'The bundling of these loans is so huge, it's difficult for us to tear apart each of those bundles and say, "OK, this bad loan is causing this securitisation to fail",' Sharon Ormsby, head of the financial crimes section in the FBI's criminal investigative division, said.

Goldman Sachs and Morgan Stanley admitted in their annual reports this week that government authorities had requested information from them, but both banks declined to specify which arms of government had made the requests.

Further reading:

Further writedowns expected for US banks

Bankers sweat over sub-prime accounting