bank froze my friend's account

1) You can approach court.
2) Amount deposited in your bank account cannot be divested by bank unless the person who deposited claims that it was mistakenly deposited.

1. approaching the Court is the only option

Get full particulars. Are you sure its bank that froze the account and not Income Tax authorities. Approach the bank and get full details as to how and why the account is frozen. And also request the bank as to who deposited the amount into your account and was it online credit? And also is there a claim? In all fairness, since the money does not belong to you and you also do not know who and why deposited such huge amount into your account, you should co-operate with the bank to rectify the mistake of wrong credit if that is the case. Court may not rule in your favour without thoroughly probing the matter and court is absolutely satisfied that the money belongs to you.

You have not posted entire facts.  What was the exact amount that was disputed?  Whether entire account was frozen or that specific amount of unknown credit not relevant to actual depositor was frozen, whether any notice was given, whether there was an inconvenience to your friend from the bank for withdrawing his own funds was experienced----Whether your friend has given any letter to the bank denying such credit etc.,......  This is not a simple issue as the amount deposited was rupees one crore and no one believes that a stranger has deposited one crore in an unknown account without depositor's knowledge and your friend might have given some blank cheques to someone as security etc., .  The bank can only obey the directions of other banks, tax authorities, law enforcement agencies and can not take any action on their own without issuing notices.  Some facts /links are missing.

Yes GLN Prasad garoo.