The former chairman of FIFA's Independent Governance Committee has urged the organisation to appoint Theo Zwanziger as its temporary president amid the ongoing corruption scandal.
Mark Pieth, who worked for FIFA from 2011 until his resignation in 2013, wants former German FA (DFB) president Zwanziger to lead world football's governing body for a two-year period.
FIFA was plunged into further crisis on Friday when the Swiss attorney general opened criminal proceedings against Sepp Blatter, who had been due to step down as president at an election in February.
UEFA president Michel Platini -- who was widely backed to win that election -- has also been questioned as a witness over "a disloyal payment" of 2 million Swiss francs from Blatter in 2011, and both men are reportedly facing an investigation by FIFA's ethics committee.
Pieth, speaking to Swiss newspaper Sonntagsblick, said the reforms that Blatter had "unleashed himself" to clean up FIFA had sparked a "revolution" and added: "Now the revolution devours all its children."
He urged Blatter to vacate his position now -- in part simply to "step out of the line of fire" -- but the decision could potentially be taken out of the 79-year-old's hands by the ethics committee should its investigation find sufficient evidence of wrongdoing.
According to FIFA statutes, Confederation of African Football president Issa Hayatou, who has been mentioned in the investigations surrounding the controversial vote to award the 2022 World Cup to Qatar, would then succeed Blatter as the caretaker president.
However, Pieth, a 62-year-old law professor, said: "That's a problem.
"Blatter's statutory successor might also be stuck with investigations. That's why it would be important to elect a transitional president fast."
Pieth also warned against handing Platini the role.
He had said earlier this summer that the Frenchman would be "the worst option and a step backwards for FIFA" and that either Zwanziger or his successor at the DFB, Wolfgang Niersbach, would be a more appropriate choice.
Pieth said that, while Platini remains a supporter of the 2022 World Cup in Qatar, Zwanziger would seek to relocate the tournament.
"Should Theo Zwanziger be elected as the president for a transitional period of two years, and I hope this will happen, then you also thwart Qatar due to labour-related reasons," he said. "Should Platini be elected, the World Cup will take place in Qatar."
Zwanziger is being sued for libel by the Qatari government and the Qatari FA over comments he made about the Gulf state, with the court case due to take place shortly before the planned FIFA presidential election in February.
Niersbach, meanwhile, has faced criticism in the German media after expressing his "bewilderment" at the news of the investigation into Blatter.
In a statement on the DFB website shortly after the news broke of the Swiss attorney general's investigation, Niersbach -- an active member of FIFA's executive committee -- had said: "Irrespective of the new developments, of which I and the other members were not informed during Friday's executive committee meeting in Zurich, the path taken must be continued."
He added that "the extent and severity of the accusations have left us speechless."
In a comment for Der Spiegel, journalist Jens Weinreich said Niersbach "either has not done his homework or is the wrong person for the job" if the news of the investigation had left him "surprised and speechless."