A FIFA ethics investigator removed from office has said that his committee was investigating "several hundred" cases of possible wrongdoing, some involving senior officials.

World football's governing body recommended on Tuesday that Cornel Borbely, along with the chief ethics judge Hans-Joachim Eckert, not be re-elected at the FIFA Congress, which takes place on May 11 in Bahrain.

Eckert led the clean-up attempt at the organisation, which has been the focus of numerous corruption allegations, and helped bring down Sepp Blatter as FIFA president.

The removal of the ethics investigators is a "setback in the fight against corruption" and "means nothing else but the end of the reform process", Borbely said in Bahrain on Wednesday.

Borbely earlier said that the "removal was unnecessary and, because of that, political", adding it is a "setback for the fight against corruption", with experience in the cases being lost.

Eckert and Borbely predicted long delays in current investigations, saying on Wednesday that there is "no period of transition" to the new ethics leadership for the ongoing cases.

"We investigated several hundred cases and several hundred are still pending and ongoing at the moment," Borbely said.

FIFA issued a statement on Tuesday saying that the Colombian investigator Maria Claudia Rojas had been nominated as the new head of the investigatory chamber, with Vassilios Skouris, of Greece, a former president of the European Court of Justice, put forward as head of the adjudicatory chamber.

The decision is set to be ratified by FIFA at its annual Congress, which convenes in Bahrain on Thursday.

The decision is controversial as critics have accused Gianni Infantino, the FIFA president, of having a personal motive to replace Eckert and Borbely, as an ethics investigation was launched against him last year.

Eckert was the judge who opened proceedings against Blatter and Michel Platini in November 2015.

Following Tuesday's decision, one FIFA council official was quoted by AFP news agency as saying: "Congress members felt that FIFA and the Ethics Commission needed freshening up."

Reform agenda in question

FIFA's decision threatens to overshadow its congress and critics will argus that it calls into question the reform agenda set by the president, who was elected last year after football's governing body was engulfed by corruption scandals and high-ranking executives were arrested in Zurich hotel raids.

Infantino had claimed to be ushering in a "new era" in after succeeding the discredited and banned Blatter.

Against this backdrop, FIFA has been trying to persuade commercial backers to sign up after many were scared off by the corruption allegations.

FIFA's leadership was able to start its congress week in Bahrain by boasting the arrival of Qatar Airways to fill the airline sponsorship category that has been vacant for more than two years.

But the deal was anticipated given that Qatar Airways is the state-owned carrier of the 2022 World Cup hosts.