Police in Frankfurt have raided the headquarters of the German Football Association (DFB) over allegations of tax evasion linked to the 2006 Fifa World Cup, prosecutors say.
The homes of DFB President Wolfgang Niersbach, his predecessor Theo Zwanziger, and former Secretary General Horst Schmid, were also searched.
It follows reports that a secret €6.7m (£4.9m) fund was set up to secure votes for Germany to host the 2006 World Cup.
The DFB denied the claims last month.
It said on Tuesday that documents were seized during the raid and that it was fully co-operating with the investigation.
About 50 officers and tax inspectors swooped in on the DFB headquarters and the homes of the three senior officials.
In a statement, the prosecutor’s office said it had opened a probe into claims of serious tax evasion linked to the awarding of the World Cup to Germany in 2006.
It said it was investigating the alleged transfer of €6.7m from “the organising committee for the DFB to the Fifa football association”.
Mr Niersbach has denied the allegations, claiming instead that the sum was used to secure larger Fifa funding.
He said the deal was agreed at a private meeting between suspended Fifa President Sepp Blatter and Franz Beckenbauer, the president of the organising committee for the 2006 World Cup.
But, speaking to Der Spiegel news weekly, Mr Zwanziger accused his successor of lying, saying it was “clear that a slush fund existed”
Mr Beckenbauer said last week he had made a “mistake” in the bidding process in 2000 to host the 2006 World Cup, but denied that votes were bought.
A former World Cup-winning captain and ex-Germany coach, Mr Beckenbauer instead supported Mr Niersbach’s claim that a payment was used to unlock Fifa subsidies.
“In order to receive a financial subsidy from Fifa, it was agreed to accept a recommendation from Fifa’s finance committee, which from today’s perspective, should have been rejected,” he said.