Belgian police raided nine of the country’s top soccer clubs including current and former champions Club Brugge and RSC Anderlecht on suspicions of financial fraud and corruption.

Searches were also carried out at the offices of KRC Genk, KV Kortrijk, KV Mechelen, KV Oostende, Sporting Lokeren, AA Ghent and Standard Liege, the federal prosecutor’s office told reporters in Brussels on Thursday.

Four people, who prosecutors didn’t identify, were charged with corruption and belonging to a criminal organization and a fifth was charged with money laundering.

Documents, cash and jewels worth at about 3.6 million euros ($4.2 million) were seized as police led 44 raids in Belgium and 14 house searches in France, Luxembourg, Cyprus, Montenegro, Serbia and Macedonia, the prosecutor’s office said. Police discovered empty boxes of luxury watches that would have been worth about 8 million euros.

The probe, which started late 2017, focuses on suspect financial operations by two brokers in the players market, including money laundering, private corruption and tax evasion. Investigators also said they found indications of match-fixing during two matches last season.

Belgium’s Pro League, sponsored by AB InBev, said in a statement it fully supports the investigation as it will “take important and decisive initiatives to tackle the root causes of the problem” such as the introduction of new regulatory frameworks “to ensure a maximum degree of integrity.”

The clubs issued separate statements confirming the visits of investigators at their premises in the last two days and saying that they are fully co-operating with Belgian police.

In a separate investigation, prosecutors in the city of Tongeren said Christophe Henrotay, a former agent of Manchester United player Romelu Lukaku, is also being probed over alleged financial irregularities regarding transactions in the nation’s division 1A.

Henrotay is accused by soccer coach and trainer Peter Smeets of retaining millions of euros from him and Belgian national team players including Lukaku at the time of their respective transfers to different football clubs, via hidden commissions.

Representatives of Henrotay didn’t immediately respond to requests for comment. He managed the transfer of Belgian goalkeeper Thibaut Courtois from Chelsea to Real Madrid for 40 million euros this summer.