Morocco beat South Africa in the bid to host the 2010 World Cup but ballot papers were deliberately miscounted, a former senior Fifa official secretly recorded by the Sunday Times alleged.
Fifa and Sepp Blatter were allegedly handed tapes of one official, Ismail Bhamjee, revealing that Morocco had won the right to host the contest, but failed to investigate the claims.
The tapes also allege that both Morocco and South Africa bribed officials.
They were recorded by the Sunday Times five years ago as part of its investigation into Fifa corruption.
In the recordings, former executive committee member Bhamjee claims that after asking colleagues who they voted for, he believed that Morocco had won the bid to host the 2010 World Cup by two votes.
Though he acknowledges that voters could have lied about who they cast their ballot for, he claims that the ballot papers were deliberately miscounted.
"After talking with everybody… Whose votes went where? We're all colleagues, you know. And then we found out that actually Morocco won by two votes," Bhamjee said the in the tapes.
The tapes contain allegations that former Fifa vice president, Jack Warner, accepted a $1m (£650,000) bribe for the Moroccan bid, but switched allegiances to South Africa, which offered him more.
In 2011, Bhamjee told the paper that Qatar won the bid to host the 2022 World Cup after paying for the votes of African delegates.
The latest allegations come with world football's governing body reeling after a series of top officials were arrested on corruption charges and the organisation's president Sepp Blatter forced to step down.