Banks are still investigating the work practices of the currency trader who is suspected of losing $750 million at AIB subsidiary Allfirst in the US.
Trader Mr John Rusnak was so successful in counterfeiting proof of bogus trades that his bank was frantically trying to verify six-month-old trades the day before the suspected fraud was made public, foreign exchange traders said today.
Mr Rusnak also apparently had agreements with at least two big banks - Bank of America and Citibank - that essentially allowed him to use their names when making trades.
Traders are not clear why he did this, or why Allfirst needed such extra backing in the foreign exchange market. But these agreements may have helped Rusnak conceal his activities, traders said.
Some of his practices could have been seen as warning signals, they said. Given the controls on checking and verifying trades that are supposed to be in operation in a currency trading room, traders said they were still surprised that Rusnak was able to hide the losses for so long.
Mr Rusnak, who worked for Allfirst Financial in Baltimore, has been suspended from his job.
His actions are being investigated by the US attorney in Maryland, the FBI and by AIB of Dublin, the parent of Allfirst. No charges have been filed against Mr Rusnak.