Franz Beckenbauer was questioned by Swiss prosecutors on Thursday concerning allegations of corruption surrounding the 2006 World Cup.
The four are suspected of fraud, criminal mismanagement, money laundering and misappropriation.
The Swiss Attorney General's Office (OAG) opened criminal proceedings against Beckenbauer and three other former high-ranking German soccer officials last September.
Beckenbauer - who headed the bidding process for Germany - said: "Today I was interviewed as part of a long scheduled hearing by the Swiss federal prosecutor".
"Beckenbauer was cooperative", the federal prosecution office said.
He is also under investigation by FIFA's ethics committee over a bribery case.
The world governing body turned down Niersbach's bid to rescind a one-year ban over the 2006 World Cup scandal in December of last year.
Tax authorities raided the DFB headquarters after it emerged that a secret payment of 6.7m euros (£4.6m; $7.2m) was made to Federation Internationale de Football Association in 2005.
The 70-year-old, a World Cup victor as a player and a manager with West Germany, was named last year by the Attorney General of Switzerland as one of four men facing proceedings.
It was allegedly provided at the request of Mr Beckenbauer, who led the committee seeking to secure Germany's right to host the event.
Beckenbauer has previously admitted to making mistakes but has denied wrongdoing.
The Austrian home of Beckenbauer, who has denied wrongdoing, was raided past year for evidence in a case that threatens his reputation.
The former defender went on to manage French side Marseille and German giants Bayern Munich.