Gurmeet Ram Rahim Singh, who has an estimated net worth of $40 (£26) million and has 50 million followers worldwide, is head of the socio-spiritual organisation Dera Sacha Sauda. He also stars in films.
And the preacher allegedly convinced up to 400 men to carry out castrations on themselves because it would bring them closer to God.
The procedures, which witnesses say were conducted at a hospital owned by Singh, took place around the year 2000 but are coming to light because those involved are speaking out for the first time, The Sydney Morning Herald reports.
Singh was charged with conspiracy involving the murder of an investigative journalist in 2002 and several female followers claim he sexually assaulted them but he has never been convicted.
The current case was brought by India’s Central Bureau of Investigation, who accuse Singh of grievous bodily harm.