Is it permissible to accept money paid to settle a debt if there is doubt about its illicit source?

If the money to be used for repaying a debt is suspected of being stolen or usurped, it is permissible to take it for your debt as long as it is merely a suspicion. However, if you are certain or highly assume that it is stolen or usurped, and there is a possibility of returning it to its owner, then it is not permissible to take it. If there is no possibility of returning it to its owner, the preponderant opinion is also that it is not permissible to take it.