Answer:
(Fatwa: 882/692=L/1430)
It was injustice of part of your brother not to pay the debt at appointed time in spite of being to do so. It is narrated in Hadith: مطل الغني ظلم(delaying payment being able to do so is injustice). But, you can receive from him only the actual amount, not the amount as well as the loss, it will be interest which has been unlawful by the Quran and Hadith.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
