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, sallallaauh alayhi wa sallam, is His Slave and Messenger.
Allaah Says in the Quran (waht means): {O you who believe! Fear Allaah and give up what remains (due to you) from Riba (usury and interest) (from now onward), if you are really believers}.
Jaabir ibn Abdullaah, may Allaah be pleased with him, narrated that the Prophet said in the farewell Hajj: “All usury of pre-Islamic times is laid down. The first usury I lay down is the usury of 'Abbaas ibn Abdul-Muttalib (i.e. his uncle). I nullify it entirely".
Therefore, we advise you to refrain from all usurious contracts. If you are able to put an end to the previous contracts that involved Riba, then you should do so, and only keep your capital, leaving all interest. If your testator had taken the debt with usury, and you (inheritor) can avoid usury, by paying the capital debt only, then you should do that.
However, if it is impossible to come out of this Riba contract, then you may continue with the current situation untill you are able to end these contracts and resort to Islamic ones instead, and we hope that Allaah will forgive you. Allaah says (what means): {Allaah burdens not a person beyond his scope}. [Quran 2: 286].
To know how to purify your wealth from this Riba, please refer to the following Fatwa 87149.
Allaah knows best.