Two members, FIFA vice-president Issa Hayatou from Cameroon and Jacques Anouma from the Ivory Coast were paid $1.5 million by Qatar, according to claims highlighted by MPs at the culture, media and sport committee in the House of Commons.
In an astonishing morning of whistle-blowing at the inquiry, claims of "improper and unethical" behaviour by four other executive committee (ExCo) members were made by former FA and England 2018 bid chairman Lord Triesman.
Two other FIFA members, Amos Adamu from Nigeria and Reynald Temarii from Tahiti, were banned by the body's ethics committee last year.
The latest developments mean no fewer than eight FIFA ExCo members - one third of the total of 24 - have either been alleged to have been or already found guilty of impropriety in relation to the 2018 and 2022 World Cup bids.
Tory MP Damian Collins said that evidence submitted by the Sunday Times, which the committee will publish, claimed that Hayatou and Anouma were paid 1.5 million US dollars by Qatar.
Collins said: "The Sunday Times' submission, and this is to be published by us later, claims that 1.5million dollars was paid to FIFA executive committee members Issa Hayatou and Jacques Anouma who went on to vote for Qatar."
Collins said the submission claimed Qatar specifically employed a fixer to arrange deals with African members for their votes.
Adamu and Temarii and four other FIFA officials were banned by FIFA's ethics committee last year after a Sunday Times investigation into World Cup bidding.
Later, Triesman later gave evidence of "improper and unethical" behaviour by four other executive committee members.
He said FIFA vice-president Jack Warner asked for money - suggested to be £2.5million - to build an education centre in Trinidad with the cash to be channelled through him, and later £500,000 to buy Haiti World Cup TV rights for the earthquake-hit nation, also to go through Warner.
Paraguay's FIFA member Nicolas Leoz asked for a knighthood while Brazil's FIFA member Ricardo Terra Teixeira asked Triesman to "come and tell me what you have got for me".
Thailand's FIFA member Worawi Makudi wanted to be given the TV rights to a friendly between England and the Thai national team, said Triesman.
He added: "These were some of the things that were put to me personally, sometimes in the presence of others, which in my view did not represent proper and ethical behaviour on the part of members of the executive committee."
John Whittingdale, chairman of the committee, said he would now be writing to FIFA president Sepp Blatter to launch an investigation into the evidence "as a matter of urgency".
Triesman added that he would undertake to provide his evidence to any FIFA inquiry.
In relation to the claims about payments made by Qatar 2022, Mike Lee, the London-based public relations consultant who worked on Qatar's bid, said he was unaware of any payments being made.
Lee, formerly communications director of the Premier League, UEFA and London's 2012 Olympic bid, told MPs: "I was working at the highest level of that bid and talking at length with the chairman and ceo and saw no evidence of any of these allegations.
"My experience is I would have had a sense if such things were going on and I had no sense of that."