Luciano Moggi, who is at the centre of an investigation into alleged corruption in Italian football, has quit as general manager of Juventus.
Moggi is one of 41 people being investigated
"From Monday I will have resigned. From this day the world of football is no longer my world," Moggi said.
"Now I'll think about defending myself from the malice said about me."
He has been linked to the publication of telephone taps involving talks with Italy football federation officials regarding refereeing appointments.
Referee Massimo De Santis, who is set to officiate at the World Cup next month, is also being investigated in the probe.
Moggi, along with Juve chief executive Antonio Giraudo, are two of 41 people under formal investigation.
Giraudo, who is also mentioned in the publication of taps, is under investigation for possible false accounting relating to transfer dealings.
Six-times European champions AC Milan as well as Lazio feature in the probe of 19 league games from last season.
In Rome, police searched the soccer federation's offices and those of the referees' association.
The crisis led incoming Prime Minister Romano Prodi to suggest that a political 'commisar' be put in charge of the Italian Football Federation (FIGC).