"I asked him what it was that finally triggered his split with Ayatollah Khomeini, just a few months before the latter's death in 1988. He said one day one of his associates, a cleric, came to him in panic saying his 13-year-old daughter was in danger of execution on suspicion of supporting an opposition group. Ayatollah Montazeri said he did his best to prevent the execution but to no avail." (thanks Nabeel)