Dieter Glietsch, the capital’s police president, has promised the incident is being investigated, telling the Tagesspiegel newspaper, “Thor Steinar clothing has absolutely no place in the police.”

The clothing brand is a particular favourite among neo-Nazis, a fact which should not have escaped a police officer working in central Berlin, Glietsch said.

“Wearing clothes which belong in the far-right scene is enough to create the suspicion of dereliction of duty, even though there are no specific clothing rules,” he said.

The case came to his attention after the officer concerned was attacked during the demonstration – demonstrators had seen his Thor Steinar jumper and figured he was a neo-Nazi, a spokesman for the left-wingers said.

Initially the police officer told his superiors the jumper was only visible after he had opened his coat to pull out his truncheon – after he had been attacked.

He later changed his story, saying he did not know the political connotations of the clothing brand.

Glietsch said he was investigating the officer. “That a police officer walks around wearing Thor Steinar clothes during the anniversary of the pogrom calls for a thorough investigation,” he said. “It is not as if in Berlin one does not know what the label stands for.”

Several retail shops across Germany have recently been shut down or are facing closure for selling Thor Steinar clothing, which sparked protests in Berlin, Hamburg and Magdeburg.