I want to know about that whether it is permissible to purchase a flat of a building from the owner who might have build that building with the money taken as bank loan and paid interest.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

There is no harm in that because after possessing a loan, it becomes a property of the debtor and is considered as a debt. What he bought with this loan became legally his property, and it is not forbidden to deal with him regarding that property, whether it is obtained by a loan with interest or not. However, a person who borrows money with interest is sinful. Lastly, we draw your attention that religious rulings are based on a reality, or a preponderant belief because there is no ruling about a matter the bases for which are only doubts.

Allaah knows best.