Updated 12.30pm

JAPAN HAS SAID it is “highly probable” that an Islamic State video, in which the group said it beheaded a second Japanese hostage, was authentic.

“After an extensive review, we believe it’s highly probable” the video is real, government spokesman Yoshihide Suga said in response to a reporter’s question about its authenticity.

When asked if the man in the video was 47-year-old journalist Kenji Goto, Suga replied: “We think so”.

The IS militants released the video yesterday purportedly showing the beheading of Japanese Goto.

In it, Goto is seen kneeling, dressed in an orange outfit, as a masked man standing beside him with a knife blames the Japanese government for his “slaughter.”

The executioner appears to be the man known as Jihadi John, speaking with a southern English accent and addressing the Japanese government.

“You, like your foolish allies in the Satanic coalition, have yet to understand that we, by Allah’s grace, are an Islamic Caliphate with authority and power, an entire army thirsty for your blood,” he said.

He then speaks directly to Japanese Prime Minister Shinzo Abe.

“Because of your reckless decision to take part in an unwinnable war, this knife will not only slaughter Kenji, but will also carry on and cause carnage wherever your people are found. So let the nightmare for Japan begin.”

The video made no mention of a Jordanian pilot also held hostage and threatened with execution.

Kenji Goto

Goto, 47, is a freelance journalist who established a video production company, Independent Press, in Tokyo in 1996, supplying documentaries on the Middle East and other regions to Japanese television networks, including public broadcaster NHK.

Goto had apparently been out of contact since late October after telling family that he intended to return to Japan, NHK reported.

In early November, his wife received email demands for about one billion yen ($8.5 million) in ransom from a person claiming to be a member of Islamic State, Fuji TV said.

The emailed threats were later confirmed to have come from a sender implicated in the killing of US journalist James Foley, Fuji TV said.

The Minister for Foreign Affairs and Trade, Charlie Flanagan, has condemned the murder.

On behalf of the Irish people I send my condolences to the family of Kenji Goto and to the government of Prime Minister Abe and the Japanese people.Kenji Goto, like other victims of ISIS’ brutality, was devoted to helping the people of Syria and we must recall his bravery and humanity, while condemning utterly the depraved barbarity of his death.

Ireland stands against the inhumanity of ISIS and its unspeakable outrages against the peoples of the Middle East and those humanitarian and media workers who place their lives at risk to assist the Syrian population.

 - © AFP, 2015 Additional reporting Christina Finn