Embattled Fifa president Sepp Blatter made the startling admission on Thurday that Qatar's 2022 World Cup bid could face a re-vote if bribery allegations are proven.
Blatter, who himself faces a contest for re-election on June 1 with Qatar's powerful Asian Football Confederation (AFC) chief Mohammed Bin Hammam, said that a Fifa inquiry into claims made by The Sunday Times that there was corruption in the vote could lead to the Fifa executive committee voting again.
He announced that the whistleblower at the centre of the claims has agreed to go to Fifa to give evidence in person.
Qatar became the first Arab and Middle East country to make a successful bid to stage the Fifa World Cup last December.
The whistleblower alleged that Fifa members Issa Hayatou and Jacques Anouma were paid $1.5 million each to vote for Qatar, according to evidence given to a Parliamentary committee by the Sunday Times. The pair deny the claims.
Blatter said the newspaper has agreed to bring the whistleblower, who had worked for the Qatar 2022 bid organisation, to Zurich to testify in person but would not be drawn on the possibility of a re-vote taking place.
The Fifa boss said that the notion that 2022 vote would be reheld was "alarming" but considered it was one that had a groundswell of popular support and was "circulating around the world."
"But don't ask me now yes or no, let us go step by step. It's like we are in an ordinary court and in an ordinary court we cannot ask: 'if, if, if'," he said.
Blatter, speaking in an interview at Fifa headquarters, added: "We are anxiously awaiting for these evidences or non-evidences in order that we can take the adequate steps.
"We will organise and the newspaper have agreed that we will bring this whistleblower here to Zurich and then we will have an investigation of this."
The interview will be conducted by FIFA general secretary Jerome Valcke and legal director Marco Villiger, and will also cover the whistleblower's claims that Nigerian FIFA member Amos Adamu had agreed to the cash-for-votes deal with Qatar only to be suspended for the vote.
Blatter said he was also keen for the independent investigation commissioned by the FA into other claims made by ex-chairman Lord Triesman to provide their findings as soon as possible - FIFA's Congress opens in 11 days.
Triesman alleged impropriety by four other FIFA members - Trinidad's Jack Warner, Thailand's Worawi Makudi, Brazil's Ricardo Teixeira and Paraguay's Nicolas Leoz - while he was head of England's 2018 World Cup bid, claiming in Parliament that they asked for cash or favours.
Blatter added: "We have to see evidence and then we will intervene. We have received the declarations made in the House of Commons but we have not received any evidence.
"The whole procedure cannot be done in 11 days but before 11 days - by April 27 - we must know whether the allegations are true or not true - or unproven. If they are not true this case is over.
"The ethics committee is already alerted and alarmed - they are not just lying on the beach - and the members will come for the Congress and can convene at very short notice."
Blatter added that he was pleased with the FA's move to appoint James Dingemans QC, a deputy high court judge, to carry out the inquiry into Triesman's claims.
"I am very happy about the direct help we have received from the FA in London because it was very important for us because the allegations were made by the former chairman of the FA," he said.
The corruption claims have overshadowed the FIFA presidential election on June 1 where Blatter is standing against Asian confederation president Mohamed Bin Hammam, who is from Qatar and played the key role in securing the 2022 tournament for his country.
Blatter has now received backing from all the continental confederations bar Asia - though this does not mean all the individual associations will follow suit.
Warner, the CONCACAF president, emailed Blatter this week giving the support of the organisation that covers football in north and central America the Caribbean.
"I have just received an email from Mr Warner saying CONCACAF will always be your home ground," said Blatter.
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