Answer:
(Fatwa: 210/206=J)
Till this time no one has appeared who had the signs and conditions of Hazrat Mahdi mentioned in hadith. A person who says that Hazrat Mahdi appeared and died too, such a person is utter liar and fabricator; it is unlawful to pray salah behind him. Try to convince your relatives that such a belief is a cause of kufr (disbelief), it must be avioded absolutely. For details you should study the book: Alamaat-e-Qiyamat.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
