Dr Ahmad Zahid said he has evidence of this and promised to reveal all at a press conference to be called by the ministry soon.
This was despite PAS deputy president Mohamad Sabu's threat to sue Dr Ahmad Zahid over the statement, as the former has maintained that he was not a Syiah follower.
"In Islam, we cannot have another mazhab (sect) because it will cause disunity among the Muslim community.
"I am looking at this from the security point of view.
"I do not want what has happened (civil war) in other countries to occur in Malaysia," Dr Ahmad Zahid said in a press conference after attending the ministry's monthly gathering here on Monday.
During his winding-up speech at the Umno General Assembly 2013. Dr Ahmad Zahid told the Malaysia Department of Islamic Development (Jakim) to take immediate action against a "PAS No. 2 leader", allegedly for being a Syiah follower.