Reference: al-Haawee min Fataawa ash-Shaykh al-Albaanee – Page 349
Question: What is the Islaamic ruling regarding [Ayatollah] Khomeini?
Response: Khomeini has a book in which he mentions the excellence of the Imaams [Hassan and Hussein et al] of the family of the Prophet ﷺ over and above the Prophets and the Messengers (‘alayhim as-salaam); [So] based upon this [statement of his] he is not a Muslim.