Finance Minister Arun Jaitley today slammed inadequate oversight by regulators and auditors as well as sloppy bank management for the Rs. 11,400-crore fraud at Punjab National Bank, and said if needed law would be tightened to punish fraudsters. Speaking on the banking scandal for the second time this week, Mr Jaitley slammed lack of ethics in certain sections of businesses and said multiple layers of auditing system chose to either look the other way or did a casual job.