Former Borussia Dortmund and Hertha Berlin midfielder Steffen Karl has admitted he offered ex-Energie Cottbus goalkeeper Georg Koch a €20,000 bribe to fix a German second-division match. Both Koch and disgraced referee Robert Hoyzer named Karl in connection with the match-fixing scandal currently engulfing German football. The 35-year-old Karl, who was arrested last Wednesday, has now confessed. "Mr Karl has admitted to prosecutors that he offered the former Cottbus goalkeeper (Georg) Koch between 15,000 and 20,000 euros to manipulate the match between Regensburg and Cottbus," said Andreas Bartholome, the player's lawyer. On the final day of last season's second division, Energie Cottbus, who Koch was playing for at the time, took on Regensburg and the goalkeeper said he received a phone call from Karl asking him to "let a few goals in" for a 20,000 euro purse. Koch hung up but claimed Karl phoned back with the same offer in a more threatening tone. When the accusation came to light Karl said: "All I can say is I sleep well at night." But new evidence has forced the former Hertha player to spill the beans and it appears he was involved with the same Croatian mafia circle as tainted official Hoyzer. Hoyzer, 25, has admitted to fixing four matches -- although he is being investigated for a total of 63 games -- and has denounced other parties including referee Dominik Marks. Marks pleaded his innocence but has since been arrested.