Multiple cash deposit and withdrawal

One of our client is having multiple cash deposit and withdrawal from the saving account. The single amount deposited was not more than Rs 49000 on any day but aggregate amount was around Rs 36,00,000 during F.Y. 2010-2011. This was reported in AIR by bank and resulted in notice by income tax since PAN number was not disclosed for this account. Now how can we justify this deposit and withdrawal to the income tax since it was personal and net balance in the account on any day was not more than Rs 2,00,000. Returns for the same as been filed. Please suggest.