FIFA is facing fresh corruption allegations over the decision to award Qatar the hosting rights to the 2022 World Cup.

The UK's Sunday Times obtained millions of secret documents - including letters, emails and bank transfers - which the paper alleges is proof former Asian Football Confederation president Mohamed Bin Hammam made payments totalling $US5 million to football officials in return for support of Qatar's bid.

The Sunday Times reports the emails prove Bin Hammam used a secret slush fund to make the payments.

Qatar has always denied that Bin Hammam lobbied for the country in the lead-up to the vote.

Australia lost out in the first round of voting for the 2022 World Cup hosting rights, with Qatar beating bids from the United States, South Korea and Japan.

The new allegations will place FIFA under new, added pressure to re-run the vote for the 2022 World Cup.

Under a cloud ... Qatar's successful World Cup bid has come under constant scrutiny. ( Getty Images: Laurence Griffiths )

Although the majority of the officials did not have a vote, the Sunday Times has alleged Bin Hammam's strategy was to win a groundswell of support for Qatar's bid which would influence the four African FIFA executive committee members who were voting in the election.

The paper also alleges it has documents which prove Bin Hammam paid 305,000 euros ($446,959) to cover Oceania's FIFA executive committee member Reynald Temarii's legal expenses.

Tahiti's Temarii could not vote in the election as he had already been suspended by FIFA after he was caught in a sting asking bogus American bid officials for money in exchange for his voting support.

The Sunday Times alleges Bin Hammam provided Temarii with financial assistance to allow him to appeal the suspension.

Doing so meant Temarii's removal was delayed, blocking deputy David Chung from voting in the 2022 election, with Chung believed to have been ready to support Australia's World Cup bid.

Bin Hammam was banned from world football in 2011 after being caught bribing voters in his attempt to be elected FIFA president.