His followers divided into three groups after him.

His followers divided into three groups after him. One group said that it was his son Ahmad. Another maintained it was Ahmad Ibn Muhammad Ibn Musā Ibn al-Furāt. And another group believed that it was Ahmad Ibn Abi al-Husain Ibn Bishr Ibn Yazīd. Their group disintegrated. One of them is Ahmad Ibn Hilāl al-Karkhi. Abu ‘Ali Ibn Humām said, Ahmad Ibn Hilāl was from the companions of Abu Muhammad (a.s).

The Shī‘a were unanimous on the deputization of Abu Ja‘far Muhammad ‘Othmān (a.s) on the account of clear instructions of al-Hasan (a.s) during his lifetime. And when al-Hasan (a.s) passed away, the Shī‘a said to Ibn Hilāl, “The congregation is with him.

Will you not accept the leadership of Abu Ja‘far Muhammad Ibn ‘Othmān and refer to him, when the Must-be-Obeyed Imam has clearly assigned him as his representative?” He said to them, “I have not heard the Imam mentioning him as his representative. I do not deny the deputization of his father [meaning, ‘Othmān Ibn Sa‘īd], though.

However, if I were certain that Abu Ja‘far were the representative of the Patron of the Age, I would not defy him.” They said, “If you have not heard, others have.” He said, “You follow what you have heard.” He did not profess the authority of Abu Ja‘far, so the Shī‘a beseeched damnation for him and manifested their disdain for him. Then the holy letter came through Abu al-Qāsim Ibn Rūh (a.s) that took the oath of damnation against him and denounced him amongst the others who were damned.

One of them is Abu Tāhir Muhammad Ibn ‘Ali Ibn Bilāl. His story and what happened between him and Abu Ja‘far Muhammad Ibn ‘Othmān al-‘Amri, may Allah lighten his visage, is well-known. He seized the assets of the Imam, which were in his hands, and refused to deliver them, and claimed that he is the representative. The congregation turned away from him and beseeched damnation for him and the famous letter came from the Patron of the Age (a.s).

Abu Ghālib al-Rāzi says, Abu al-Hasan Muhammad Ibn Muhammad Ibn Yahyā al-Ma‘ādhi said, One of our men followed Abu Tāhir Ibn Bilāl after the dispute had occurred. Then he turned away from him and returned to our congregation. I asked him about the reason. ويقول بالاجابة للمحارم وتحليل نكاح الرجال بعضهم بعضا في أدبارهم، ويزعم أن ذلك من التواضع والاخبات والتذلل في المفعول به وأنه من الفاعل إحدى الشهوات والطيبات وأن الله(عز و جل) لا يحرم شيئا من ذلك.