New Delhi : The Reserve Bank of India (RBI) conducted a special audit of Kolkata-based lender Srei Infrastructure Finance and its subsidiary, Srei Equipment Finance, and the findings may be worrying for bond buyers and India's top lenders because it may reveal some financial trouble at the non-banking finance company (NBFC) that has over Rs 30,000 crore in outstanding loans. The company has, however, described the audit as a 'regular' regulatory scrutiny.