But in a dramatic twist, FIFA investigator Michael Garcia, who authored the report, released a separate statement calling into question the summary of his findings by Eckert.
"Today's decision by the chairman of the adjudicatory chamber contains numerous materially incomplete and erroneous representations of the facts and conclusions detailed in the investigatory chamber's report. I intend to appeal this decision to the FIFA appeal committee," he said in a statement.
'Envelopes full of cash'
In the 42-page statement document published on Thursday, ethics committee chairman Eckert said: "The main challenge with regard to corruption is proving it," adding: "To assume that envelopes full of cash are given in exchange for votes on a FIFA World Cup is naïve."
Eckert "fully concurs with the relevant findings," according to the document, but "the occurrences at issue, were… only of very limited scope".
"In particular, the effects of these occurrences on the bidding process as a whole were far from reaching any threshold that would require returning to the bidding process, let alone reopening it," the document said.
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The ethics committee now considers the matter closed, effectively clearing the winning bids of Russia and Qatar to host the tournament in 2018 and 2022 respectively.
Garcia– who spearheaded the 18-month investigation into the corruption allegations – is calling for the findings of the report to be released. FIFA President Sepp Blatter has previously maintained that a public disclosure of the probe was not on the table.
Eckert's summary of the investigation - and former New York district attorney Garcia's approval as an independent voice - were seen as critical for the reputation of the soccer governing body.
In recent months, key sponsors had voiced concerns over corruption allegations. Earlier this month, Emirates Airlines, one of FIFA's six top-tier sponsors, decided not to extend its agreement beyond 2014 due to the allegations.
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Qatar's Supreme Council for Delivery and Legacy, in charge of executing the 2022 bid, was quick to respond to Eckert's summary on Thursday.
"As we have noted in the past, we cooperated fully with the Ethics Committee's investigation and continue to believe that a fair and appropriate review will demonstrate the integrity and quality of our bid," the council said in a statement, noting that it would consider the report "thoroughly" before commenting further. A call for additional comment by CNBC was declined on Thursday.
For gas-rich Qatar, the World Cup is less integral to its economic ambitions, but rather serves as a deadline and a source of momentum for some $200 billion of dollars in infrastructure spending.
England soccer body slammed
Meanwhile, the English Football Association (FA) rejected the report's note on its conduct. The FA was described in the summary as having "damaged the integrity of the ongoing bidding process".
"We do not accept any criticism regarding the integrity of England's bid or any of the individuals involved," the FA said in a statement.