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.
The prohibition of the interest-based loan (with Riba) is related to the one who took it, and not the item he bought with it.
Based on this, there is nothing wrong if the heir benefits from the estate if he inherits the deceased. This is so, even if the deceased (who left inheritance) had borrowed the money with Riba and bought the property with that loan. At-Taaj Wal-Ikleel fi Sharh Mukhtasar Khaleel reads:
"It the prohibition is related to the person (for having obtained ill-gotten money), then what he possess (i.e. buys with the ill-gotten money) becomes part of his wealth." [End of quote]
Allah Knows best.