Qatar has never doubted the "clean" record by which it won the bid to host the 2022 World Cup, a top organising committee official said Thursday after FIFA cleared Doha of corruption.

The tiny gas-rich state also voiced readiness to help in hosting the 2015 Africa Cup of Nations.

"We were confident that any impartial investigation was to show that our record was clean and contains no irregularities," Hassan al-Thawadi, secretary-general of the Qatar 2022 organising committee, told AFP.

"We were confident of ourselves and of the work we had done," added al-Thawadi, speaking in Riyadh where world football leaders, including FIFA president Sepp Blatter, were gathered for the opening evening of the Gulf Cup of Nations.

The ethics committee of the football's world governing body FIFA on Thursday cleared Qatar and Russia of corruption and ruled out a re-vote for the 2018 and 2022 World Cup tournaments despite widespread allegations of wrongdoing.

Even though the report had admitted a series of worrying episodes in the bidding for the tournament, as well as the 2018 World Cup in Russia, it said there was not enough evidence to justify reopening the process.

In a break with FIFA tradition, the 2018 and 2022 tournaments were awarded at the same time, in 2010, leading to claims of horsetrading in the bidding process.

As concerns grew, FIFA appointed Michael Garcia, a former US federal prosecutor, to head up the inquiry into the 2018 and 2022 tournaments.

His 350-page report was handed to FIFA on September 5.

It summed up a year-long investigation that involved interviewing more than 75 witnesses and compiling a dossier with more than 200,000 pages and audio interviews.

The main controversy revolved around Qatar and how it was awarded the 2022 competition which was initially to be played in the summer when temperatures reach the upper-40s Celsius.

It also considered claims by international labour organisations that working conditions for migrant workers employed in the construction of the stadia were less than satisfactory.

Amnesty International on Wednesday criticised the "woefully insufficient" steps taken by Qatar so far to end abuses of migrant workers in the Gulf country.

Meanwhile, head of the Asian Football Confederation (AFC), Shaikh Salman Bin Ebrahim Al-Khalifa, hailed the results of the probe.

"I am satisfied that Qatar has been absolved of any misconduct in their bid for the 2022 World Cup," he said.

President of the Association of National Olympic Committees, Sheikh Ahmad Al-Fahad Al-Sabah, also praised the outcome, adding that the Qatari "record is successful and honours the whole region".

Despite Qatar escaping a re-vote, Thursday's ethics committee report still raised serious concerns over its campaign.

The report again probed the role of Qatari Mohammed bin Hammam, a former member of the FIFA executive committee who was banned from all football activity in 2012.

In June, Britain's Sunday Times alleged that bin Hammam paid more than $5 million (four million euros) to officials around the world before the 2010 vote to drum up support for the tiny Gulf state.

However, the report states that payments were designed to bolster his bid for the FIFA presidency in 2011 rather than to manipulate Qatar's 2022 World Cup hopes.

The FIFA ethics committee meanwhile said that England had violated bidding rules in its failed attempt to host the 2018 tournament, which was awarded to Russia.

The accusation was immediately rejected by England's Football Association which insisted it had conducted a "transparent bid."

Qatar's decision to sponsor the 2010 Confederation of African Football (CAF) Congress in Angola to the tune of $1.8 million was also brought into question during the FIFA investigation.

"It remained unclear how much the event did cost. The Investigatory Chamber of the FIFA Ethics Committee concluded that this connection, when viewed in the context of the lack of transparency in the record, created a negative impression," added the report.

"However, the circumstances presently relevant were not suited to affect the integrity of the FIFA World Cup 2018/2022."

Meanwhile, head of the Doha's Football Association Sheikh Hamad bin Khalifa bin Ahmed al-Thani said in a statement that "if officially asked, Qatar is ready to offer any help in hosting the African Cup due to its strong relation with Issa Hayatou, president of the Confederation of African Football."

Morocco had said since early October that its call for a postponement was due to the deadly Ebola pandemic, but CAF, lost patience with the North Africans and threw them out of the competition, with a heavy fine likely to follow.