In a nutshell, the LOC fraud relates to the blatant misuse of letters of credit by officials of the state Veterinary Department since 1985. The LOC is a regulatory mechanism devised by the state government to keep expenditure under control. When the Government earmarks, say, Rs 10 crore fora project, the entire amount is not handed over to the department concerned in one go. It is released in phases and LOCs are issued, which can be cashed when required. The system was introduced in Assam a few years ago.