The Swiss special prosecutor has opened criminal proceedings against FIFA president Gianni Infantino relating to dealings with the country's attorney general Michael Lauber.
Lauber offered to resign from his position last week after a court found he covered up an undisclosed meeting with the head of football's governing body and lied to supervisors while his office probed corruption relating to FIFA.
Stefan Keller was appointed as special prosecutor to review criminal complaints against Infantino, Lauber and other individuals.
A statement from the Swiss Federal Council said Keller had found "indications of criminal conduct".
Proceedings have consequently commenced against Infantino and the chief public prosecutor of Upper Valais, Rinaldo Arnold.
Keller has also requested permission to open proceedings against Lauber.
Both Infantino and Lauber have previously denied any wrongdoing.
The Federal Council statement added: "The presumption of innocence applies to attorney general Michael Lauber, FIFA president Gianni Infantino and chief public prosecutor Rinaldo Arnold. The special federal public prosecutor is independent in his activities."
Last week, a Bern court partially upheld a salary reduction for the period of one year for Lauber, who faced disciplinary proceedings after the supervisory authority for his office believed he breached official duties by meeting several times with Infantino.
A court statement last week said Lauber's sanction – a salary cut of eight per cent that was reduced to five per cent by the court – was justified based on "several breaches of official duty".
Infantino was voted in as the successor to disgraced former FIFA chief Sepp Blatter in February 2016.
Blatter, who was president for 17 years, and former UEFA counterpart Michel Platini were suspended from all football-related activity by FIFA in December 2015.
The adjudicatory chamber of FIFA's ethics committee ruled a payment of two million Swiss francs, authorised by Swiss Blatter to former France captain Platini, constituted multiple infringements of the FIFA code of ethics. Both men denied wrongdoing.
Blatter later saw an eight-year ban reduced to six on appeal but the Court of Arbitration for Sport (CAS) dismissed an appeal to have the suspension quashed in December 2016. CAS reduced Platini's sanction to four years.