Purity: Prohibition of Exhumation

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 630:

Exhuming the grave of a believer – i.e. opening his grave – is unlawful, even if the grave belongs to a child or an insane person. However, there is no problem if the body has completely decomposed and become dust.

-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)