SHAFAQNA – The Grand Ayatollah Khamenei answered questions about usury loan.
Question: What is usury loan? Is the interest paid to depositors by banks considered as usury?
The Grand Ayatollah Khamenei: Usury loan is the extra amount added to the loan which the borrower must pay back to the lender; but the interest which is paid by banks to deposits which banks use to take part in correct religious contracts on behalf of the depositor is not usury and there is no problem.
Source: PERSIAN SHAFAQNA