Hafiz Muhammed Saeed, the head of the Islamic State's Pakistan wing, is believed to have been killed in Tirah Valley on Thursday in an IED explosion.
Security officials said that Saeed and two other men were trying to assemble an improvised explosive device when it went off, killing them instantly, according to Pakistan's The Express Tribune.
However, the terror group has not confirmed Saeed's death.
Saeed was among the several members of the Tehreek-e-Taliban, who shifted allegiance to the Islamic State, and was made the leader of the Isis Khorasan, the Pakistani wing of the militant outfit.
Saeed, 42, hailed from the Orakzai Agency area, a tribal region near the Afghanistan border, and was a spokesperson of the TTP.
The Islamic State had put up a video online this January of Saeed pledging allegiance to Isis.
Some Twitterati were also speculating about Saeed's death.
— Majeed Babar (@journalist777) April 17, 2015