A plan for England to play a friendly in Thailand to win backing for their 2018 World Cup bid was "a form of bribery", investigators were told.
Ex-Football Association chairman Geoff Thompson made the admission when interviewed during an inquiry into the 2018 and 2022 World Cup hosting bids.
On Tuesday, football's world governing body Fifa released the full 2014 report of the investigation.
That followed leaked extracts being published by German newspaper Bild.
The 422-page report was written by former Fifa independent ethics investigator Michael Garcia.
He quit in protest when the organisation only released a 42-page summary of his document.
That version cleared Russia and Qatar, winners of the 2018 and 2022 hosting rights respectively, of corruption allegations.
However, it was critical of the actions of some Fifa executive committee members and some of the bidding teams, including England's.
The full report goes into more detail about this conduct, and also cites an interview given by the 2018 England World Cup bid chief Thompson around the national team's plans to travel to Thailand to secure a vote for their bid.
The offer to stage the friendly was made only eight days before the vote in 2010 to decide the 2018 and 2022 hosts. The offer was withdrawn three weeks later, by which stage it was clear Thailand had not supported the English bid.
The FA was open at the time about the friendly being arranged to win support.
But Garcia's report reads: "Top English football officials recognised that arranging friendlies with a team from an executive committee's home country in order to advance the England 2018 bid was improper.
"Geoff Thompson candidly told the investigatory chamber he 'didn't think it was appropriate' to organise the proposed England-Thailand match-up or other friendlies targeting teams associated with executive committee members 'because I think it's a form of bribery'.
"The game's cancellation only underscores the improper relationship between the 24 November 2010 offer to play the game and the 2 December World Cup vote."
Why has the report been released now?
Fifa said its president Gianni Infantino had always intended to release the full document, but its former ethics chiefs had refused to publish it.
The former chairmen of the ethics committee, Cornel Borbely and Hans-Joachim Eckert, were replaced in May after completing four-year terms.
Speaking in October 2014, Eckert said: "Publishing the report in full would actually put the Fifa ethics committee and Fifa itself in a very difficult situation legally."
The pair moved to clarify their position later on Tuesday, issuing a statement which said the decision not to publish "was in line with Fifa rules" as some cases brought as a result of the report were still ongoing.
They added: "To this day, Mr Infantino has never contacted us and asked for a publication."
Fifa said it had intended to discuss the release of the report at a meeting next month, but added: "As the document has been illegally leaked to a German newspaper, the new chairpersons have requested the immediate publication of the full report in order to avoid the dissemination of any misleading information.
"For the sake of transparency, Fifa welcomes the news that this report has now been finally published."
Qatar 2022 officials said they welcomed the report's publication, although they questioned "the timing of the leak", and said it represented "a vindication of the integrity of our bid".
Analysis - What does it tell us?
BBC sports editor Dan Roan
Ever since ex-Fifa investigator Michael Garcia resigned in protest at the way his landmark corruption probe was handled in 2014, his secret report has been one of sport's great mysteries. Did it contain information that might force Fifa into a sensational re-vote for the hosting of the 2018 and 2022 World Cups?
The fact Fifa itself has finally published the report (albeit only after it had been forced to by a leak to a German newspaper), suggests it does not. Yes, the bidding process was highly dubious, and yes, Fifa executives were evasive, uncooperative and exploited "a culture of entitlement". But that is hardly a surprise. And with Garcia denied full access to bank accounts, and no subpoena power, explosive allegations were always unlikely.
There are new details over the lengths most of the bid teams went to in order to curry favour with Fifa's discredited executives, including the FA. Amid highly embarrassing revelations, we now know Prince William and David Cameron were present when a vote-trading deal was agreed by former FA and England 2018 bid chairman Geoff Thompson, in breach of anti-collusion rules.
But other details were already known. Garcia reinforces the perception of a culture of greed that it is now widely accepted to have gripped football's governing body.
But events have overtaken his report, with most of the former Fifa executive committee members that voted for Russia and Qatar already banned for unethical behaviour, indicted or under scrutiny. Criminal investigations into the bidding process continue.
While it does not appear to be a 'smoking gun', the report will be uncomfortable reading for Qatar. Among other details, Garcia says its 2022 bid used the Doha-based academy Aspire to "curry favour with executive committee members", and that this "served to undermine the integrity of the bidding process".
Qatar's hosting is already under renewed scrutiny amid a diplomatic crisis with its neighbours over its alleged support of extremism. Meanwhile, as it prepares to stage the final of the Confederations Cup, 2018 host Russia has been forced to fend off new doping allegations.
But with Garcia writing back in 2014 that he did "not intend to pursue formal investigatory proceedings against any individual bid team member", both hosts crucially appear to be in the clear.
Why was the investigation started?
Garcia was appointed as Fifa's independent ethics investigator in 2012 and asked to look into the 2018 and 2022 World Cup bidding process following claims of corruption around the bids.
They included allegations that disgraced Qatari football official Mohamed bin Hammam made payments totalling $5m (£3m) to football officials in return for their support for the Qatar bid.
Qatar vehemently denied votes were being bought and said Bin Hammam had not been acting in an official capacity.
Garcia spent two years investigating the claims and looked into all nine hosting bids - including one by the English FA.
Russia won the right to host the 2018 World Cup, beating England as well as joint bids by the Netherlands/Belgium and Spain/Portugal.
At the same time, in December 2010, Qatar won the 2022 bid ahead of Australia, Japan, South Korea and the United States.
What were the findings?
Fifa released a 42-page summary of Garcia's final report in 2014. It cleared Qatar of any wrongdoing, ending any possibility of a re-vote for a new 2022 host.
However, the report said there were "certain indications of potentially problematic conduct of specific individuals" - though Bin Hammam's payments were judged to be for his personal political interests, not the 2022 bid.
Russia, meanwhile, was also cleared of any wrongdoing, though the investigation had "only a limited amount of documents available for review" because the Russian team's computers had been destroyed.
The English FA was accused of acting improperly in trying to win votes and flouting bid rules, while Australia too received criticism.
In a statement, the Football Federation Australia said they had repeatedly acknowledged "that the bid process for 2018 and 2022 was deeply flawed and that mistakes were made by the Australian bid team".
What was the reaction?
While Russia and Qatar welcomed the report, the FA baulked at the criticism.
The man who led the investigation, Garcia, complained Eckert's precis of his report was "erroneous".
Eckert denied that, insisting of his published summary: "A lot of my report was word for word from the Garcia report."
Garcia subsequently quit and Fifa's critics said it showed the shortened, released report had been a "whitewash" and called for the full report to be released.
Almost three years later, they have got their wish.