German football legend Franz Beckenbauer is one of six men being investigated for their part in the country's 2006 World Cup bid.
The ethics committee of world governing body Fifa has decided to act after examining a report commissioned by the German Football Association (DFB).
In October, Beckenbauer, 70, said he made a "mistake" in the bidding process for which he took "responsibility".
Germany beat South Africa 12-11 in the vote, which took place in July 2000.
Who are the six being investigated?
- Franz Beckenbauer: Former vice-president of the DFB, president of the 2006 World Cup local organising committee (LOC) and former member of the Fifa executive committee.
- Wolfgang Niersbach: Former president of the DFB, vice-president of the LOC and current member of the Fifa and Uefa executive committees.
- Helmut Sandrock: Former secretary general of the DFB and tournament director of the LOC.
- Theo Zwanziger: Former president of the DFB, vice-president of the LOC and former member of the Fifa and Uefa executive committees.
- Horst Schmidt: Former secretary general of the DFB and vice-president of the LOC.
- Stefan Hans: Former chief financial officer of the DFB and chief financial officer of the LOC.
German news weekly Der Spiegel reported last year that an alleged slush fund of 6.7 million euros (£4.8m) was used to buy votes for Germany. The allegation was denied by the DFB.
Beckenbauer, Zwanziger, Schmidt and Hans are to be investigated for "possible undue payments and contracts to gain an advantage in the 2006 World Cup host selection", while Niersbach and Sandrock will be investigated for a "possible failure to report a breach of the Fifa code of ethics".
Beckenbauer was the head of the World Cup organising committee, which reports allege made a payment to Fifa in return for a financial grant.
He captained West Germany to victory as hosts at the 1974 World Cup and was coach when they next lifted the trophy, in Italy 16 years later.
The former defender went on to manage French side Marseille and German giants Bayern Munich, where he is now honorary president.