Michael Garcia, the lawyer tasked with investigating corruption in the 2018 and 2022 World Cup bidding process, has resigned as head of Fifa's ethics committee.
His decision comes the day after Fifa rejected his appeal against Hans-Joachim Eckert's 42-page summary of his findings, which Garcia described as "erroneous" upon its release in November.
In his statement, Garcia questioned the lack of leadership in world football's governing body and queried whether the organisation is capable of change.
His resignation letter read: "For the first two years after my July 2012 appointment as independent chairman of the Fifa ethics committee's investigatory chamber, I felt that the ethics committee was making real progress in advancing ethics enforcement at Fifa. In recent months, that changed.
"It now appears that, at least for the foreseeable future, the Eckert decision will stand as the final word on the 2018/2022 Fifa World Cup bidding process.
"While the appeal committee's decision notes that further appeal may be taken to the Court of Arbitration for Sport, I have concluded that such a course of action would not be practicable in this case. No independent governance committee, investigator, or arbitration panel can change the culture of an organisation.
"Accordingly, effective today, December 17, 2014, I am resigning as independent chairman of the investigatory chamber of the Fifa ethics committee."
Eckert, chairman of Fifa's adjudicatory chamber of the Ethics Committee, released his summary, which found no evidence of wrongdoing on the part of the successful Russia 2018 and Qatar 2022 bids, leading to call for the full report to be published.