Praise be to Allah.
We put this question to Shaykh Muhammad ibn Saalih al-‘Uthaymeen, may Allaah preserve him, who answered as follows:
If he is going to give it to you on the basis that it is diyah (blood money), then you should not take it, because he is a kaafir and you are a Muslim; a Muslim cannot inherit from a kaafir, and diyah is a kind of inheritance. If he is going to give it to you just to make you feel better (as a gift), then there is nothing wrong with taking it. And Allaah knows best.