The Investigative Committee said Tuesday that they now suspect that a deputy mufti of the Stavropol region who died when his car exploded was murdered after initial reports deemed the episode an accident.

Kurman Ismailov, deputy mufti of the southern region, was killed Monday evening while traveling in his car in the capital of North Caucasus Federal District of Pyatigorsk.

The blast was caused by a bomb equivalent in strength to four kilograms of TNT, the Investigative Committee said in a statement Tuesday. Earlier reports had classified the explosion as an accident.

Investigators feel the murder "could be linked to the professional activity of Ismailov," or as the result of a personal argument, the statement said.

According to the Kavkazsky Uzel news portal, Ismailov was "one of the most influential Muslim figures in Russia."

He was detained last year on suspicion of illegal explosives possession, but was shortly released without being charged.

Stavropol region mufti Muhammad Rakhimov told Interfax that no one had threatened Ismailov.

"He would try to smooth out all conflicts, and he would never get into conflicts," Rakhimov said, according to the report.