Is my friend obligated to inform the heirs of a corrupt official, a thief, and a drug dealer about the true nature of their illicitly acquired wealth, and is it permissible for the heirs to use this money?

One must differentiate between wealth that is unlawful in itself, such as stolen or plundered money, which must be returned to its owners and is not permissible for the one who took it or their heirs, and wealth that is unlawful due to its earning, such as bribery and drug dealing, which is not permissible for the one who earned it but is permissible for their heirs according to the preponderant opinion.

Based on this, it is not advisable to inform the heirs of a bribe-taker or a drug dealer about the true nature of the wealth, as a form of covering up for a Muslim, because it is permissible for them. As for the wealth of a thief, if stolen items are found in the inheritance, the heirs must be informed to return them to their owners or their heirs. If the owners are unknown, they should donate it as charity, and it is not permissible for them to benefit from it. Stolen items that the thief spent before their death are considered a debt upon them and must be disbursed from the inheritance before its distribution.