Shaikh Muqbil bin Haadi al-Wadi’ee (may Allah have mercy upon him) was asked:
Two brothers share in building a house. So, one of them takes money from a bank and the second brother does not know and he (the first one) does not tell him (the second one) except after the house is built. So what is obligatory upon the second brother?
“I hope that there is no sin upon him because he did not know. Next, the sin is upon the one who directly [deals with usury]. As for the one who was afflicted with this and he did not directly [deal with it], then there is no sin upon him. The sin is upon the one who directly [deals with it]. Cautiousness is to leave it off and there is a difference between cautiousness and prohibition”
Faisal bin Abdul Qaadir bin Hassan