Is it permissible for me to benefit from an amount of EGP 90,0 from an investment certificate, knowing that the principal amount is EGP 10,0, and that the bank took out a loan without my knowledge to increase the certificate’s interest? Am I sinful because of this loan? And must I break the certificate to pay it off, or wait until the end of its term?

The investor's ignorance of the usurious transaction absolves him of sin, but he must cancel the investment contract immediately upon learning the religious ruling, if possible, and not wait for the contract term to end. As for the profits he earned before knowing the impermissibility of the transaction, it is more cautious to dispose of them by spending them on charitable causes. Some jurists have held that it is permissible for one ignorant of the contract's impermissibility to benefit from what he earned from it.