The case was being investigated “with all rigour,” the ministry said in response to a report in Der Spiegel news magazine.

“We are deeply ashamed,” the ministry said, adding that it would not tolerate any extremism within the ranks of the military.

Der Spiegel reported evidence of an extremist grouping within the Berlin-based battalion, which numbers around 1,000 and performs ceremonial duties.

The group is reported to refer to itself as the “Wolfpack.” Its leader is said to have racially abused soldiers of non-German origin.

According to Der Spiegel, a 32-year-old non-commissioned officer has been seen wearing a T-Shirt showing a black sun with the legend “Sonnenstudio 88” (Solarium 88) on the front and “We are brown” in German on the back.

The number 88 correlates with HH as the eighth letter of the alphabet and is associated with the banned Hitler salute. The Nazi party’s initial paramilitary wing wore brown.

Apart from its ceremonial duties in welcoming foreign leaders and parading at German ceremonies, the battalion is tasked with securing the government offices.