Bayern Munich president Uli Hoeness admitted he is being investigated by the German Revenue Administration for tax evasion.
The former West Germany international made the revelations as the Bavarian giants cruised to a 6-1 demolition of Hannover.
The 61-year-old Hoeness refused to discuss the finer details of the investigation but did reveal they centred on a Swiss bank account.
"I filed a voluntary disclosure about the account to my accountant at the tax office in January 2013," Hoeness is quoted as saying by German magazine Focus.
"I trust fully in the work of the authorities involved in the case and ask for there to be respectful refrain from further enquiries."
Bayern sealed the Bundesliga championship earlier this month and face Barcelona in the semi-finals of the Champions League on Tuesday.