Stewarts’ wife Penny Lancaster shared a video that shows the singer in the Abu Dhabi desert appearing to use his hand to imitate a beheading.
After the video appeared online, some people pointed out that it has a resemblance to ISIS propaganda videos and Lancaster has since deleted the clip from her Instagram account.
However, the clip is still available on YouTube, and you can see Stewart, dressed in a white blouse and sunglasses, appear to make a cutting gesture across a friend’s neck as they kneel on the sand.
The 72-year-old singer has apologized for his actions and insisted that he was just “larking” around before his concert in the Arab Emirates and re-enacting a Game of Thrones scene.
“Understandably, this has been misinterpreted and I send my deepest apologies to those who have been offended.”
The alleged beheading gesture provoked outrage on social media due to its similarities to videos which show Islamic State militant Mohammed Emwazi, also known as Jihadi John, brutally murdering British aid workers captured by ISIS.
Dressed head-to-toe in black, with a mask leaving only his eyes visible, the ISIS executioner first appeared in a video threatening American journalist James Foley while brandishing a knife.
WATCH BELOW: ISIS militant known as ‘Jihadi John’ from beheading videos identified
People on Twitter have labelled Stewart’s actions as “clueless” and “insensitive.”
The rock icon made headlines in January after he appeared to be drunk on live TV while helping out with the Scottish FA Cup draw.
He begins his Las Vegas residency on March 15.
With a file from Adam Frisk