Several hundred cases of wrongdoing in football were under active investigation when FIFA ousted its ethics leadership, the outgoing Swiss prosecutor Cornel Borbely said on Wednesday.
FIFA has decided to replace Borbely and German judge Hans-Joachim Eckert at the head of the ethics committee following sweeping changes announced by the ruling council of world football's governing body.
Colombian prosecutor Maria Claudia Rojas and Greek judge Vassilios Skouris, who was president of the European Court of Justice from 2003 to 2015, are to be installed in their places.
Borbely said the process of bringing corrupt officials to justice will now stall as new ethics officials have to learn how to navigate the global FIFA structures.
"We investigated several hundred cases and several hundred are still pending and ongoing at this moment," Borbely said in Bahrain, where FIFA is holding its annual congress. "Imagine where FIFA would be today without an ethics committee."
Borbely failed along with Eckert to be nominated for re-election by the FIFA Council headed by president Gianni Infantino.
Borbely said his "removal was unnecessary and because of that political" and called it a "setback for the fight against corruption."
Eckert and Borbely have been with the ethics committee since a revamp with greater independence in 2012, and have banned multiple officials during the biggest corruption crisis in FIFA's history, including disgraced former president Sepp Blatter.
FIFA said that its ruling council proposed Skouris and Rojas for approval by the congress of all nations on Thursday.
Borbely said there's "no period of transition" to the new ethics leadership for the ongoing cases.
"They do not have the experience from day zero," Borbely added. "You have to develop this practice, this knowhow. It's a question how long it takes for the new chamber to investigate these cases to the level that will bring the success."
Both Borbely and Eckert had said they wished to continue their work and branded their departures damaging to world football.
A statement from Borbely and Eckert read: "Their impending removal at the FIFA Congress will greatly set back the work of the ethics commission and means the de facto end of FIFA's reform efforts.
"It must be assumed therefore that in the medium and long term the whole of world football will suffer because of this decision.
"The work of the credible and independent ethics committee was and is an important part of the FIFA reforms, on which the trust of the public and FIFA stakeholders should have been rebuilt.''
The statement said that a loss of confidence in FIFA's commitment to reform was now "inevitable'' and the "already-battered image'' of world football's governing body would be tarnished yet further.
It added that the removal of Borbely and Eckert was "obviously politically motivated.''
It said: "It seems the FIFA hierarchy has valued its own and political interests higher than the long-term interests of FIFA.''
Aside from the personnel changes, FIFA also confirmed how many slots each of its six confederations would get at the 48-team World Cup in 2026.
As widely anticipated, UEFA sees its allocation grow from 13 to 16, with the other regional bodies all seeing more substantial increases.
Two of the new slots will be decided by what FIFA described in a statement as an "intercontinental playoff tournament involving six teams,'' while the hosts' automatic place will be deducted from their confederation's quota.
In the event of co-hosts, as looks increasingly likely for 2026, the number of automatic places will be decided by the council.
On the subject of who will host the 2026 tournament, the council decided against ending the race now by simply giving it to the joint North American bid from Canada, Mexico and the United States but rivals from other confederations only have until August to declare their hands.
The short time-frame means the North American bid is almost guaranteed victory, which should be confirmed at next year's FIFA Congress.
Other decisions reached by the council include lifting the ban on Iraq being able to play matches in their own country, providing the security situation remains stable in the proposed venues, and London being named as the host of the Best FIFA Football Awards 2017 on October 23.
Information from the Press Association was used in this report.