The Central Bureau of Investigation (CBI) has conducted searches at the office of GTL Infrastructure Ltd (GTIL) in Mumbai after registering an FIR against the company and unidentified officials of banks in a loan-fraud case of over Rs 4,000 crore. The banks are accused of assigning dues of Rs 3,224 crore of GTIL to an asset reconstruction firm for Rs 1,867 crore without securing their loans from collateral securities.