Zwayer received a six-month ban in 2005 for his part in a match-fixing scandal.
The 43-year old Zwayer was handed the ban from DFB, the German Football Federation, after he had worked as an assistant referee for Robert Hoyzer, who was convicted of having taken bribes to fix several 2. Bundesliga matches that he officiated.
Allegedly, Zwayer had accepted a €300 bribe ahead of a game involving Wuppertaler SV, but Zwayer later slightly redeemed himself by informing the German FA of Hoyzer’s match fixing, with three other referees backing up Zwayer.
It wasn't until the German publication Die Zeit released “The Zwayer File” in 2014 that the German public learned of Zwayer’s ban. Meanwhile, Hoyzer was banned for life.
Zwayer's return to action in 2021 prompted Jude Bellingham to criticize his permission to officiate Bundesliga-matches and his performance in the clash between Borussia Dortmund and Bayern Munich in December that year, saying: “You give a referee who has match-fixed before the biggest game in Germany, what do you expect?”
It's only five days since Zwayer was in charge of another crucial match on Danish turf when FC Midtjylland faced Nottingham Forest in the Europa League.