Former FIFA president Sepp Blatter called for an investigation into his successor Gianni Infantino, after Switzerland's attorney general admitted meeting the current boss of world soccer's governing body.
The attorney general, Michael Lauber, told journalists on Wednesday that his meetings with current FIFA boss Infantino were "normal and regular, especially in complex cases".
The Football Leaks website alleges that Infantino offered favors to a senior Swiss prosecutor, Rinaldo Arnold, in a bid to foster a relationship with Lauber, possibly to obtain privileged information about the FIFA probe.
Lauber added that his office was disclosing the meetings for the sake of "transparency".
According to Football Leaks, the informal meetings occurred in the spring of 2016, a few months after Infantino took charge of FIFA and vowed to restore its credibility, which had been shaken by the corruption-plagued 17-year leadership of Blatter.
The body that oversees Lauber's office, known as the AS-MPC, told AFP on Wednesday that while Lauber was not under investigation, it was examining the propriety of the meetings between Infantino and the attorney general.
Blatter reacted to Wednesday's news by telling AFP: "The FIFA Ethics Committee must do something and open an investigation into Mr Infantino.
"Where is the transparency preached by Mr Infantino during his election? He should report himself to the Ethics Committee to show that he is transparent."
Blatter added: "Infantino met Mr Lauber several times, whereas I have been questioned by him just once since a procedure against me was opened in September 2015."
Swiss prosecutors have pursued some 25 individual cases since a raid on a Zurich hotel in May 2015 led to the arrests of a number of FIFA executives and exposed the corrupt underbelly of world soccer.