for packing credit loans u should look into the cost of export sales made for wich the loan is obtained...compute the cost of production & vouch the Bills of inputs materials & services used in producing them...look after if any thing was pledged after the shipment of final goods, though initially there may not be any hypothecation wen the loan was granted..

1. Packing Credit Loans : available upto 90% of forex order , loan is in IRS, tennure 180 days or shipment date whichever is earlier.

2. Foreign Bill Purchase : available 100% of Forex bill negotiated less packing credit loan, loan is in IRS( converted value date is negotiation date), tennure 180 days or actual date of realization, whichever is earlier.

3. Post Shipment Credit,: deferred payment system of 2 above, same criteria 

thanks for the response . hope it will help in conducting the audit ...