What is the ruling on exhuming the graves of Jews and disbelievers to extract treasures, especially given the accounts of the Companions exhuming the grave of Abu Righal and extracting a golden branch?

The story of Abu Righal's grave being exhumed was reported by Abu Dawud, but Al-Albani deemed it weak. The Hanbalis used it as proof that it is permissible to exhume the graves of polytheists if there is money in them, as the Companions did with Abu Righal's grave. Some scholars have permitted this in old graves whose land owner is unknown, such as pre-Islamic graves, and the money found therein is considered akin to a buried treasure (rikaz) whose owner is unknown. A condition for this is that the state does not prohibit it.