"Today (Thursday) I was interviewed as part of a long scheduled hearing by the Swiss federal prosecutor and I answered his questions," the former chairman of Germany's 2006 bid committee said.
"Out of respect for the very correct federal prosecutor's office, and also at his request, I will not speak any more about this case," added Beckenbauer.
The Swiss investigation is focusing on a payment of 6.7 million euros made by the German Football Federation (DFB) to world football's governing body FIFA in 2005.