FIFA auditing and compliance chief Domenico Scala has resigned in protest at reforms of world football's governing body.
Scala is angered by changes announced at this week's FIFA Congress that will empower the FIFA Council and, in his opinion, erode the independence of committees.
The news comes as a blow to FIFA president Gianni Infantino, with Scala calling for his departure to serve as a "wake-up call".
"On the occasion of its meeting of yesterday, the FIFA Congress has delegated the election, or the dismissal respectively, of the members of the independent supervisory bodies - such as the Ethics Committee, the Appeal Committee, the Audit and Compliance Committee - to the exclusive competence of the FIFA Council," read a statement.
"With this decision, it will henceforth be possible for the Council to impede investigations against single members at any time, by dismissing the responsible Committee members or by keeping them acquiescent through the treat of a dismissal.
"Thereby, those bodies are factually deprived of their independence and are in danger of becoming auxiliary agents of those whom they should actually supervise.
"I am consternated about this decision, because it undermines a central pillar of the good governance of FIFA and it destroys a substantial achievement of the reforms.
"For this reason, I herewith declare my immediate resignation as the President of the Audit and Compliance Committee of FIFA."
Scala continued: "Since the announcement of the resignation of the former President last June, I had pushed on various levels nd vigorously for the elaboration and adoption of a comprehensive reform package for FIFA.
"At the end of February this year, the Congress finally approved a future-oriented package and thereby paved the way for FIFA to a more credible future.
"This decision still fills me with satisfaction and also a certain pride. Whether the adopted reform points will now really be filled with flesh and blood remains open for the time being.
"My resignation shall also be a wake-up call and shall give backing to those persons involved, who genuinely advocated for implementing the reforms until today.
"I would like to prompt all of them: Keep going like this, FIFA needs and deserves your commitment and you consistent action."