Belgian authorities were investigating Tuesday whether an alleged jihadist from a Brussels suburb had appeared in a video by the Islamic State group that shows the beheadings of Syrian military personnel.

The Belgian daily Het Laatste Nieuws reported that one of the men featured in the video looked like Abdelmajid Gharmaoui, who is currently on trial in his absence in Belgium for membership of a jihadist group.

It published an image of an unmasked man with a partial beard and long curly hair taken from the IS video, alongside a photo of a similar-looking man identified as Gharmaoui that the paper said was taken in Syria in July 2013.

Several European countries are investigating whether their nationals feature in the video, which shows the simultaneous beheadings of 18 Syrian prisoners and, separately, of kidnapped US aid worker Peter Kassig.

"We can neither confirm nor deny (the report of a Belgian in the video). The analysis is underway," a spokeswoman for the Belgian interior ministry said.

The Belgian federal prosecutor's office was also investigating.

But the mayor of the Brussels suburb of Vilvorde, where Gharmaoui lived before going to Syria in 2012, said Gharmaoui "is not at all in the video" and the report is "completely wrong".

"We don't recognise anyone of Vilvoorde in it. I can be sure 99 percent that no-one from Vilvoorde is in it," he said.

Gharmaoui is being tried in his absence in the northern Belgian port city of Antwerp with 45 other alleged members of the Islamist group Sharia4Belgium, which is accused of being one of the main sources of Belgian jihadists.

The prosecution has called for him to be sentenced to 10 years in prison for belonging to a terrorist group.

Het Laatste Nieuws reported that Gharmaoui had indicated on Facebook that he was in Dabiq, the northern Syrian city where, according to the IS video, the beheadings took place.

It quoted an intelligence source as saying it was "almost certain" the images it printed were of the same man.