The players had harsh words for the match official and his assistants after the Zebras fell victim to a late winner from the Eurofighters in their DFB-Pokal clash
Referee Tobias Stieler showed the guests four yellow cards and two reds during the encounter on Karlsruher's home soil, and he has now been subjected to, along with assistant Dr Manuel Kunzmann, heavy scrutiny from the Nordrhein-Westfalen side.
"Before [the match, referee Tobias] Stieler came into the locker room and arrogantly told us to change our football socks. Apparently something was wrong with the colours," MSV captain Goran Sukalo told reporters afterwards.
During the match, according to Sukalo, the referee allegedly threatened protesting players: "Get lost, or all of you will be sent off."
After Karslruhe's winner in the 88th minute, goalkeeper Felix Wiedwald saw red for throwing the ball towards the middle of the pitch, trying to encourage his team-mates into turning the match.
The 31-year-old captain continued, saying that Daniel Brosinski, was even threatened with violence after the match: "Kunzmann said to Daniel, you are going to get slapped."
Match assistant Kunzmann has since rejected the accusations, telling Bild that they "do not correspond with neither the choice of words nor the facts".
Karlsruhe move on to the third round of the DFB-Pokal after their victory.