FIFA's chief ethics investigator Michael Garcia has criticised the culture of secrecy at the world governing body and called for greater transparency.
Garcia, who has been investigating the bidding process for the 2018 and 2022 World Cups, said he had been operating under conditions more suitable for "an intelligence agency".
He called on the people running FIFA to show leadership and publish the 430-page report - FIFA president Sepp Blatter has said that to do so would threaten witness confidentiality.
Garcia, speaking at an event in London, said: "The investigation and adjudication process operates in most parts unseen and unheard.
"That's a kind of system which might be appropriate for an intelligence agency but not for an ethics compliance process in an international sports institution that serves the public and is the subject of intense public scrutiny."
He added: "Transparency is not intended to embarrass certain individuals by airing dirty laundry or to harm the organisation by showing what went wrong, it's the opposite.
"Where the institution has taken significant steps forward and made that progress transparency provides evidence of that to the public."