Adult ISIS Fighter in Child Executioner Video Killed, Official Says Man watched as young boy appeared to murder two men in chilling video.

 -- A notorious ISIS fighter featured in the shocking video this month of a boy appearing to execute two prisoners with a handgun has been killed in battle, a counter-terrorism official said today.

Abu Saad al-Dagestani was the nom de guerre of an ISIS terrorist shown in the gruesome Jan. 13 tape overseeing what ISIS claimed was the execution of two alleged "Russian spies" by a boy under 11. Al-Dagestani was first reported killed in jihadi tweets on Jan. 15, which claimed he was "martyred" near the embattled Kurdish town of Kobani on Syria's border with Turkey.

"We do think he was killed," a counter-terrorism official familiar with military operations around Kobani by the U.S.-led coalition told ABC News today.

The video, apparently produced by an ISIS media outlet and shared on Twitter, was seven minutes long and featured “confessions” by the two men. In a heavily-edited section, the boy, called a “lion’s cub,” was shown firing a pistol at the heads of the men, who each fall, apparently lifeless.

The boy appeared to have long hair and was dressed in black next to the adult overseeing him, al-Dagestani -- whose true identity is not known but was believed to be among many foreign fighters from Dagestan or Chechnya -- who wore a long beard, winter cap and carried both a pistol and a shoulder-slung rifle.

Officials declined to comment on the video's authenticity, but military sources and others said they suspected the executions were staged, noting the absence of bullet impacts and blood splatter. Another former counter-terrorism official, however, previously told ABC News the murders looks fairly real to him.

ISIS is well known for its sophisticated disinformation program, which is part of a highly-sophisticated media messaging committee that specializes in shocking western audiences with cinematic scenes of mass-decapitations and executions.

ISIS releases through its local affiliates in Syria and Iraq often multiple videos a day they produce depicting horrific executions for a variety of alleged violations of religious Shariah law or their own twisted rules. Most involve beheadings or amputating limbs in graphic bloodlettings.

Tweets announcing the death of al-Dagestani appeared on both ISIS-linked accounts as well as anti-ISIS Peshmerga accounts.