The Fifa ethics investigator who spent 18 months and £6m compiling a report into the controversial 2018 and 2022 World Cup bidding race has quit his post in disgust, departing with a broadside against the organisation’s culture and practices.

Michael Garcia resigned after his appeal against the decision to publish what he described as an “erroneous” summary of his 430-page report was rejected on Tuesday. As he did so he criticised the “lack of leadership” at world football’s governing body.

The Fifa president, Sepp Blatter, in Marrakech for a meeting of the executive committee, said he was surprised by Garcia’s decision. But few others were, with Garcia making his distaste for the way Fifa had handled his investigation increasingly plain.

Michel Platini, the Uefa president who voted for Qatar but has called on Blatter to stand down as promised next year, said Garcia’s exit was a “new failure” for Fifa. Jérôme Champagne, the former Fifa executive who is challenging Blatter for the presidency, called it “a step backwards”.

The US attorney said there was no point taking his appeal to the court of arbitration for sport. “No independent governance committee, investigator, or arbitration panel can change the culture of an organisation,” he said.

Garcia said the 42-page summary published in November by the German judge Hans-Joachim Eckert, which effectively cleared the 2018 hosts Russia and the 2022 hosts Qatar of serious wrongdoing during the chaotic bidding process, contained “numerous materially incomplete and erroneous representations of facts and conclusions”.

The former US attorney for the southern district of New York also revealed that Blatter and the Fifa executive committee attempted to refer him to the organisation’s disciplinary committee in September after he publicly called for the report to be published in full.

He reiterated that his report had “identified serious and wide-ranging issues with the bidding and selection process” despite the fact that he did not have the power to compel corrupt former Fifa officials to cooperate or to seize evidence.

Garcia, who works for the US law firm Kirkland & Ellis, has been scrabbling to salvage his reputation ever since the Eckert summary was released and widely condemned.

He signed up to operate under an ethics code that made clear it was in the gift of the ethics committee to choose only to publish “the terms of the decision”. He also agreed to protect the anonymity of his 75-plus witnesses. But in a speech in London in September he argued it should still be possible to publish the report in full and suitably redact evidence to protect the identity of whistleblowers, warning Fifa’s leadership that it required a wholesale culture change. It was that intervention that caused the executive committee to try to refer him to Claudio Sulser’s disciplinary committee.

He said that in the first two years following his appointment in July 2012 he felt the ethics committee was making “real progress” but that there had been a change in recent months. “The issues raised by Mr Eckert’s selection and omission of material from the report, and his additional comments, went far beyond the initial transparency concerns,” said Garcia.

He said a paper he filed on 24 November to Fifa showed why “when viewed in the context of the report it purported to summarise, no principled approach could justify the Eckert decision’s edits, omissions and additions”.

Garcia’s appeal was rejected on procedural grounds, with the Fifa appeals committee arguing that Eckert’s summary was an opinion rather than a judgment and as such there was nothing to appeal against. The five cases already opened against individuals as a result of Garcia’s investigation will presumably be picked up by an acting chairman who will be appointed by the executive committee at Thursday’s meeting, most likely his deputy Cornel Borbély.

They include cases involving the German former Fifa executive committee member Franz Beckenbauer and three current members – Ángel María Villar Llona of Spain, Thailand’s Worawi Makudi and Michel D’Hooghe of Belgium.

Bonita Mersiades, the former Australia 2022 executive who had her own complaint against her confidentiality as a whistleblower being apparently breached by Eckert dismissed, said she welcomed Garcia’s decision.

“He joins Judge Günter Hirsch who resigned from the previous ethics committee on similar grounds three years ago. I also welcome the fact that Mike Garcia agrees with what many of us have long stated – that Fifa is incapable of reform or cultural change with its current leadership,” she said.

Garcia’s decision will ratchet up pressure on Blatter to restore some form of confidence in his so-called reform process. “I am surprised by Mr Garcia’s decision. The work of the ethics committee will nonetheless continue and will be a central part of discussions at the exco meeting in the next two days,” said Blatter.

In the wake of a wave of corruption allegations that swamped Fifa in 2011, Blatter reformed the ethics committee into a new twin-chamber arrangement, with Garcia heading the investigatory arm and Eckert overseeing the adjudicatory chamber.

At their meeting in Marrakech, the head of the audit committee, Domenico Scala, will update Fifa executives on his deliberations over how much of the Garcia report they should be allowed to see and they will also vote on a motion tabled by the German Theo Zwanziger that it should be published in full. Others, including the American Sunil Gulati, the British Fifa vice-president Jim Boyce and the Concacaf president Jeffrey Webb, have also called for full publication.

Zwanzinger also warned Qatar that they could yet lose the 2022 World Cup if they failed to improve their treatment of migrant construction workers. “Qataris must deploy, by a 10 March 2015 deadline, the independent commission – tasked with regularly monitoring human rights conditions at World Cup construction sites and note progress – as demanded in the Piper report,” Zwanziger told Sport Bild magazine. “Until now apparently not much has happened,” he said.

The FA chairman, Greg Dyke, attending a match between the British Army and the German Army match in Aldershot to commemorate the Christmas truce in the first world war, also said he was disappointed at Garcia’s resignation and Fifa’s refusal to release his full report. Dyke has consistently said that the leadership at Fifa has to change if its culture is to be overhauled.