Asia's troubled football body elects a new leader on Thursday after a bitter campaign dominated by claim and counter-claim of outside interference, and even allegations of human rights abuses.

Two years after vote-buying accusations prompted the eventual downfall of former president Mohamed bin Hammam, the Asian Football Confederation (AFC) is at risk of new controversy as delegates gather to choose his successor.

All three leading candidates for the presidency have been accused, at some point, of either corruption or allowing outside powers to meddle in the vote, tempering hopes of a new era of openness and transparency.

Accusations, denials and counter-claims have flown thick in recent days, lending a testy atmosphere to proceedings as representatives of the AFC's 46 members meet at a five-star hotel in downtown Kuala Lumpur.

If the battle has been hard-fought, it's because the stakes are high: the AFC, the world's biggest football confederation, has significant revenues and influence across a vast region stretching from the Middle East to Oceania.

In a possible indication of the vote's importance, FIFA president Sepp Blatter, who was instrumental in the spectacular fall of Hammam, is one of the prominent personalities present in the Malaysian capital.

Three main candidates are in the running to complete bin Hammam's current term, which concludes in 2015. The Qatari stepped down last year after allegations of bribery and financial wrongdoing, and is barred from football activities.

Sheikh Salman bin Ebrahim Al Khalifa is the favourite, but the Bahraini royal has been on the defensive over vote-buying allegations and claims that he oversaw the arrest of footballers during a crackdown on pro-democracy protests.

Sheikh Salman has also hit back over comments, by disgraced former FIFA vice president Jack Warner, that he paid a British journalist to launch a smear campaign against bin Hammam when he challenged for the presidency in 2009.

The UAE's Yousef Al Serkal is also confident about his chances, and has been perhaps the most persuasive about cleaning up Asian football after vowing to reveal his allowances and launch a "whistle-blower" anti-corruption scheme.

However, Al Serkal is a friend of bin Hammam, a connection which will worry some voters -- especially after an accusation this week, by an ally of Sheikh Salman, that the Qatari businessman was meddling in the election.

Worawi Makudi of Thailand, a long-standing but controversial presence on the Asian scene, is the third serious contender. Worawi, who has faced down corruption accusations in the past, is also a bin Hammam ally.

Saudi Arabia's Hafez Ibrahim Al Medlej is considered an outsider and he told AFP this week that he was likely to make a late withdrawal to avoid diluting the Middle East vote.

Meanwhile the Kuwait-based Olympic Council of Asia has stayed silent on claims that it manipulated the 2009 election for Sheikh Salman, and also on accusations that it is trying to interfere with the current process.

Chinese press speculated that the shock decision of caretaker leader Zhang Jilong not to stand was taken by the country's sports administration, in order to maintain OCA support for keeping badminton and table tennis in the Olympics.

Three Bahrain-focused human rights groups have been vocally involved, and have urged FIFA to block Sheikh Salman's candidacy and investigate claims he took part in a purge of players and officials who were arrested and abused.

Sheikh Salman is also standing against Qatar's Hassan Al Thawadi for a seat on FIFA's executive committee, with Australia's Moya Dodd an uncontested candidate to become the AFC's mandatory female vice president.

Dodd, North Korea's Han Un-Gyong and Palestinian candidate Susan Shalabi Molano are also vying for two female seats on the AFC's executive committee.

Whoever wins the battle for the presidency, he will face a difficult task in uniting the diverse body after the divisive election campaign, and during the truncated term before the next election in 2015.

"The member associations are split not in half, but in several parts," a source close to Zhang warned AFP in February, when he revealed that the Chinese interim leader would not contest the vote.

He added: "The election itself could be not only a split of the votes, but also a split of the hearts."