Zurich-based FIFA's reputation depends on resolving allegations about Qatar's selection as 2022 World Cup host, according to the organisation’s anti-corruption panel chaired by Swiss law professor Mark Pieth.
The advisory group known as the Independent Governance Committee (IGC) gave its full support on Wednesday to a FIFA investigation of the 2018 and 2022 World Cup votes, led by ethics prosecutor Michael Garcia.
"The ethics committee should not rest until there is a conclusive answer," Pieth wrote in a report to FIFA board members, some of whom agitated last month to remove Garcia from the case.
"If FIFA is to emerge from the scandals of recent years it must now produce a convincing and transparent answer to any issues relating to hosting decisions, either to confirm that the suspicions are, sadly, well founded or to demonstrate that they are groundless," the report said.
The comments were published in Pieth's 15-page final report to the FIFA executive committee, which voted for Qatar and Russia as World Cup hosts in December 2010.
After FIFA’s Swiss president Sepp Blatter promised to reform the scandal-hit governing body in 2011, the board appointed Pieth to lead the independent governance committee advisory group which insisted on creating an independent ethics court to tackle corruption.
“This explicitly included allegations in relation to World Cup hosting decisions and the IGC singled out this issue including the decision to award the tournament to Qatar as one that required further investigation," Pieth wrote on Wednesday.
Garcia's position was supported by Pieth, who urged FIFA board members to assist the former United States Attorney and Interpol vice-president.
"The IGC's view was that only appointing a competent and experienced professional outsider to this role would enable FIFA fearlessly to investigate allegations of corruption at the heart of FIFA," Pieth said. "FIFA and all involved individuals must therefore fully and unconditionally cooperate with Mr. Garcia's investigation."
Moves to disrupt Garcia's probe were revealed by reformist board members who joined FIFA's hierarchy after the controversial World Cup vote.
Garcia reportedly upset some of the 13 voters who remain in office by arriving unannounced in Zurich to quiz them during a week of committee meetings.
The American lawyer and his investigating team are also seeking interviews worldwide with people who worked for the nine World Cup bid candidates, and offered anonymity to whistleblowers who had evidence of wrongdoing.
Garcia is expected to report this year to the ethics panel's judging chamber led by Joachim Eckert of Germany, which will decide sanctions.
Though Blatter has said Russia and Qatar cannot be stripped of a tournament, it is unclear how the ethics committee could seek to use its authority.
"If allegations are confirmed, FIFA must ensure that the consequences are meaningful," Pieth wrote.
swissinfo.ch and agencies