The investigation into the bidding for the 2018 and 2022 soccer World Cups found no significant evidence of corruption that would cause Russia, which will stage the 2018 tournament, or Qatar, which will do so in 2022, to lose the right to host.

Hans-Joachim Eckert, the German judge who heads the adjudicatory arm of FIFA’s ethics committee, released a report on Thursday after reviewing the work of Michael J. Garcia, a former United States attorney and the head of the investigatory chamber of the ethics committee. In his 42-page summary of Garcia’s report, which is said to be more than 400 pages, Eckert wrote that while Garcia found some potential ethics violations by Qatar and Russia, the discoveries were “far from reaching any threshold that would require returning to the bidding process, let alone reopening it.”

In fact, the heaviest criticism with regard to ethical violations during the bidding process was directed at two losing bids: England’s attempt to stage the 2018 tournament, and Australia’s bid for the 2022 event. The United States, which bid to host the tournament in 2022, was not found to have committed any significant wrongdoing.

Eckert indicated in his report that Garcia should bring charges against individuals suspected of committing violations but closed the investigation into the bidding process as a whole. FIFA issued a statement saying it welcomed the opportunity to pursue planning for the two tournaments, though it still remained unclear when the Qatar tournament would be played.

Holding the tournament in the summer, its traditional period of play, is now seen as unfeasible in Qatar, meaning that a winter tournament — possibly as late as November and December of 2022 — is a possibility.

Eckert’s report did little to quell criticisms of FIFA’s transparency, and it will almost certainly increase pressure to release the findings of Garcia’s full investigation. While Garcia and other soccer officials have called for Garcia’s report to be made public (with appropriate redactions), Eckert has said that confidentiality issues preclude that from happening. In his summary, Eckert reiterated that full publication of the investigative report was “impossible.”

The voting in 2010 on which countries would host the two tournaments was seen as strange from the beginning. Voting on two World Cup hosts simultaneously was unprecedented, and many thought it invited vote-trading. A report about a cash-for-votes scheme appeared in the British newspaper the Sunday Times before the voting was even conducted. Those revelations led to the suspension of two members of FIFA’s executive committee before the vote.

In considering the 2018 host, the 22-member committee went through two rounds of balloting before Russia received the necessary 12 votes to win the bid. The other candidates were England; a joint bid from Spain and Portugal; and a dual application by the Netherlands and Belgium.

When it came to the vote for the host of the 2022 tournament, four rounds of voting were required before Qatar received 14 votes. It edged out the United States, which received eight votes. South Korea, Japan and Australia were eliminated in earlier rounds.

Both selections were notable — Russia will be the first country in Eastern Europe to host the event, and Qatar will be the first nation in the Middle East to do so and the surprising results quickly led to questions about the bidding and voting process.

News media reports about impropriety began to trickle out almost immediately, and it quickly became difficult to keep track of just who was accusing whom of what. Two members of the selection committee — Jack Warner of Trinidad and Tobago and Mohamed bin Hammam of Qatar — were later removed amid allegations of unethical behavior, including payments from Bin Hammam to Warner and others.

In an odd twist, another member of the executive committee, the American Chuck Blazer, reported Bin Hammam and Warner to FIFA’s ethics committee. Two years after emerging as a whistle-blower, however, Blazer was suspended by FIFA for “various breaches of the code of ethics.”

In all, at least six of the 22 voters who awarded the next two World Cups have been connected to serious allegations of impropriety. In the years since, FIFA has changed the voting process to involve all 209 member nations, as opposed to only the executive committee.

Garcia, who became known for prosecuting the former governor of New York, Eliot Spitzer, spent millions of dollars in his investigation of FIFA, gathering evidence and conducting interviews all over the world. He did not have subpoena power and at times encountered resistance from FIFA officials, who for years have been plagued by allegations of corruption. Three members of the executive committee declined to participate in his investigation, the report said, and two others could not be contacted.

As recently as June, Franz Beckenbauer, a former star player for Germany and a member of the executive committee, was suspended by FIFA’s ethics committee after refusing to answer questions from Garcia. Beckenbauer subsequently agreed to respond.