Prayer: Praying on the Property of a Deceased Debtor
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 862
If a dead person owes money in alms tax (zakat) or to people, there is no problem in using his property with the consent of his heirs, provided that the use does not conflict with the paying of his debt; for example, [there would be no problem in] performing prayers in his house. Similarly, if the heirs pay his debt, take it upon themselves to pay his debt, or keep aside the amount of his debt from his estate, there is no problem in using his property even if this causes it to be ruined.