The investigation is looking into potential breaches of criminal law by government officials, regulators and executives at the two banks. The Office of the Attorney General has set up a monitoring system to take action immediately on any issues that fall within its area of responsibility. Both UBS and Credit Suisse declined to comment. Experts say the investigation could be probing breaches of secrecy provisions, trading on inside information or the wiping out of some bondholders as planned under the deal.