BOCHUM (Germany) (AFP) Four suspected ringleaders of what is believed to be European footballs biggest fraud scandal went on trial in Germany on Wednesday, accused of fixing more than 30 matches across Europe. The quartet, who have not been named, could be jailed for up to 10 years if found guilty of fraud in a trial that will question the integrity of lower league football across the continent. The trial will focus on 32 games played in Germany, Belgium, Slovenia, Hungary, Croatia and Switzerland, mostly last season, where it is alleged dozens of players or referees were bribed to influence the matches. In total, police have investigated nearly 300 games in 15 countries in a surveillance operation which has spanned the continent. Bets totalling two million euros (2.8 million dollars) are said to have been placed on the matches involved, resulting in winnings in the region of 1.6 million euros. In Germany, the games in question involve a German Cup match, games in the national leagues second division and regional leagues. Most of the matches involved are from the lower divisions in the respective countries across Europe, but a Europa League and European Under-21 Championships qualifier have also come under the spotlight. In the Europa League, European footballs second biggest domestic tournament behind the Champions League, a Group E match between FC Basel and CSKA Sofia on November 5, 2009, is under suspicion. And an Under-21 qualifying international between Switzerland and Georgia on November 18, 2009, will also be part of the evidence against the quartet. But the German Football Federation (DFB) look to have had their blushes spared as none of the games in question are in the Bundesliga, Germanys top domestic league, but have said they are keeping a close eye on the case. I dont know what will emerge from this trial, but we will react accordingly, said the DFBs referee commissioner Herbert Fandel. German football still bears the scars of match-fixing after referee Robert Hoyzer was given a two-year jail sentence after it emerged in January 2005 he had rigged a German Cup match. Hoyzer was initially suspected of betting on the Paderborn-Hamburg German Cup match in which he awarded two dubious penalties and sent a Hamburg player off as Paderborn won 4-2 after a highly controversial game. But investigations showed Hoyzer had links with a Croatian syndicate and the number of potentially guilty parties, including referees and players, reached a total of 25. Hoyzer was banned for life by the DFB and the disgraced official claimed that the illegal betting ring went all the way up to European footballs governing body UEFA.