This image grab taken from a video released by the Islamic State and identified by SITE Intelligence Group on September 2 2014 purportedly shows
This image grab taken from a video released by the Islamic State and identified by SITE Intelligence Group on September 2 2014 purportedly shows "Jihadi John", the pseudonym of Mohammed Emwazi, holding a knife as he speaks to the camera in a desert landscape before beheading 31-year-old US freelance writer Steven Sotloff. Picture: AFP

NEW YORK — A eulogy for the Islamic State’s most notorious executioner appeared online in the group’s official, English-language magazine on Tuesday, confirming that the militant known as "Jihadi John" was killed in an air strike last year in northern Syria.

The US military said in November that it was "reasonably certain" that the militant, whose name was Mohammed Emwazi, was killed in an air strike near Raqqa, Syria, a stronghold of the Islamic State. But confirmation had proved elusive.

The eulogy in the magazine, Dabiq, seemed to erase any doubt. It identified Emwazi by his assumed name, Abu Muharib al-Muhajir, and said he had been killed on November 12 when the car he was riding in was hit by an air strike carried out by a remotely piloted drone. The car was destroyed and he was killed instantly, according to Dabiq.

Emwazi, a naturalised British citizen born in Kuwait, rose to prominence in 2014 when the Islamic State released separate videos of a masked man who spoke English with a British accent beheading the journalists James Foley and Steven J Sotloff. Among his other victims were Kenji Goto, a journalist, and Haruna Yukawa, an adventurer, both Japanese; Peter Kassig, an American aid worker; and Alan Henning and David Cawthorne Haines, British aid workers.

"His harshness towards" non-Muslims, the article said, using a derogatory Arabic word, "was manifested through deeds that enraged all the nations, religions and factions of kufr, the entire world bearing witness to this." Kufr is the Arabic word for disbelief.

The Washington Post revealed his identity in February, touching off intense examination of the causes of radicalisation among Muslim immigrants in Europe.

Civil liberties advocates criticised any official British attempt to kill Emwazi as possibly unlawful, in a debate that paralleled the criticism over the Obama administration’s decision to target and kill Anwar al-Awlaki, a US-born cleric, in Yemen in 2011.

Prime Minister David Cameron of Britain defended the strike targeting Emwazi as an act of self-defence, and the US considers such strikes against specific militant leaders to be lawful acts of war or self-defence.

British officials were unable to stop Emwazi from travelling to Syria in 2013, although he had been identified as a security threat years earlier.

As a British citizen, he personified the concerns of security forces worried about a resurgence in homegrown radicalism inspired by the hard-line ideology of the Islamic State. Foreign fighters have been pouring into Syria from Western countries.