I would like to ask if someone received an inheritance from his/her relative whose earnings had some haram things like interests and he or she knows this, what is he or she supposed to do?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

If the matter is as you mentioned in question, then they should specify the percentage of usury in the money of the deceased and distribute it in charity for needy Muslims.

By doing so, the remaining money becomes lawful for him, Allah willing. If he is unable to specify, he should estimate the percentage of usury and distribute it in charity.

Allah knows best.