BRUSSELS — A Belgian politician apologized after an old picture emerged on Friday of him stripped to his underwear and draped in a Nazi flag, describing the incident as a hazing stunt gone wrong and a “crass mistake.”

The compromising image of Germain Dalne, a 26-year-old town councillor from Nivelles in southern Belgium, was made public by the newspaper L’Avenir after resurfacing on social media.

“Let’s be clear: it’s no small matter to find yourself with a Nazi flag on your back,” Dalne, who sits in opposition on the council for the center-right MR party, told AFP in a statement.

“This was a crass mistake, but one without any political or ideological connotation,” he said, adding: “I reiterate my sincerest apologies.”

According to Dalne, the picture, showing him from behind clad in a Swastika-emblazoned flag with blue boxer shorts poking out beneath, was taken during a scout camp several years ago.

In the course of a “far too drunken” evening, Dalne said he and others had swiped the flag from a stash in a nearby field that was destined for historical reenactments.

“I was hazed, as others were too — I ended up in my underwear with the flag on my back,” he said. “At the time, we were given a stern telling off by our scout leaders and immediately apologized.”

The Nivelles section of the centrist Les Engages party, which leads the town council, issued a statement calling the incident “deeply shocking and unacceptable.”

“No excuse — be it age, context or drunkenness — can trivialize the use of such a heavy symbol of hatred and historical suffering,” they wrote on Facebook.

However, the party also cautioned against “public debate turning into a lynch mob” — as well as warning of the “risks of excessive alcohol consumption, especially among the young.”