The head of bankrupt United States brokerage firm MF Global has told a congressional committee he has no idea where its clients' money has gone.
In what's shaping up to be one of the biggest corporate scandals of the year, an estimated $US1.2 billion is missing from clients' accounts at MF Global.
Jon Corzine headed MF Global for 20 months after stints as a Democrat Senator and chief executive of Goldman Sachs.
He told a US House of Representatives committee hearing that he did not knowingly move money from segregated customer accounts.
He says many transactions occured in "those last chaotic days" and he is not aware of all of them.
"As a consequence it would be very hard for me to speculate why or where that shorfall took place," he said.
It is extremely rare for a former US congressman to have to testify in a federal investigation.