My father borrowed money from a harsh moneylender who charged him exorbitant interest. He signed 7 blank cheques as security. If we report the chequebook missing and file a police complaint, can we invalidate those cheques?

Reporting a chequebook missing and filing a police complaint may not necessarily invalidate the cheques. Under Indian law, a blank cheque can be legally filled by the payee with any amount, and the drawer is legally bound to honour it.