The saga begun in 2018, when City said allegations originally published in German newspaper Der Spiegel - that they had disguised investment from owner Sheikh Mansour as sponsorship revenue in order to subvert rules that limit clubs' financial losses - were "entirely false".

The club said the claims came from "illegal hacking and out of context publication of City emails" as part of an "organised and clear attempt" to smear the club.

When that was put to Bourdon, he said: "All this victimisation or criminalisation of those who collect evidence, it's really disgusting."

The documents leaked by Pinto were key in Uefa then ruling that City had committed "serious breaches" of financial regulations, handing the club a two-year ban from European competitions in 2020.

But it was then overturned by the Court of Arbitration for Sport (Cas) later that year, a panel ruling that "based on the evidence in front of it... the majority of the panel is not comfortably satisfied that the arrangements discussed in the leaked emails were in fact executed… In the absence of a link being proven… the majority of the panel finds that Uefa’s theory on disguised equity funding remains unsubstantiated".

It also found that City had committed a "severe breach" by failing to co-operate with Uefa's investigation, with an initial £25m fine reduced to £8m.

In 2021 it was revealed that City's legal team was challenging both the jurisdiction of Premier League arbitrators to investigate, and a request to disclose documents to the panel.

In 2023, the Premier League charged City with breaching rules requiring the club to "provide accurate financial information" relating to sponsorship revenue and operating costs between 2009 and 2018. It has also accused the Premier League champions of not co-operating with its four-year investigation.

In a statement at the time, City said it was "surprised by the issuing of these alleged breaches… particularly given the extensive engagement and vast amount of detailed materials that the Premier League has been provided with. The club welcomes the review of this matter by an independent commission, to impartially consider the comprehensive body of irrefutable evidence that exists in support of its position.

"As such we look forward to this matter being put to rest once and for all."

City are contesting all charges.

In June, Pinto reportedly claimed, external that he had handed over more documents and data relating to European clubs - including information relevant to the City case - to French anti-corruption investigators, saying he was "confident they will find criminal relevancy".

When pressed on the matter, Bourdon said: "Some months ago, we went to Paris at the invitation of the financial prosecutor… and he opened all the data."

"I know that there are some documents which could bring the opening of a huge new criminal investigation against the most prominent European football clubs, including in England… and these solid pieces of evidence one day will be presented to the clubs."

He said he could not reveal which clubs it involved, nor the precise nature of the information held.

The French National Financial Prosecutor (PNF) noted Pinto's "essential co-operation", and said his assistance would help "relaunch procedures that are already under way or lead to new procedures being opened".

City have declined to comment.

Claiming to want "to show the hidden side of football", Football Leaks shared millions of documents with media outlets in the European Investigative Collaborations (EIC) consortium, a network of investigative journalists.

They included revelations on ‘third-party ownership’, the salaries of Argentina great Lionel Messi and Brazil forward Neymar, undercover talks regarding the creation of the European Super League, and alleged cases of tax evasion by several top footballers.

Paris St-Germain also admitted that scouts had racially profiled young players following an investigation based on documents made available by Football Leaks. The club denied responsibility.

A self-taught computer mastermind, Pinto was arrested in Hungary in 2019 and extradited back to Portugal. Released from custody in August 2020, he has remained under police witness protection because of security concerns.

Pinto insisted his actions were in the public interest, but last year he was convicted on five counts of "illegitimate access" to IT systems and three counts of "correspondence violations", along with the attempted extortion against the investment fund Doyen Sports. Prosecutors alleged that Pinto sought between £429,400 to £858,800 from the head of Doyen in order to stop publishing compromising documents.

When challenged over the illegality of his client's activities, Bourdon said: "Of course, he didn't find all this information in a church… He was very young, he has been naive… he should have been acquitted.

"Football should be grateful to him," insists Bourdon. "Tax administrations should be grateful to him."

"I hope that one day someone will shake the hand of Pinto and say 'thanks to you, you did a tremendous job, and you will deserve a reward… for what you did'."

Bourdon said Pinto had received death threats, and it was "very difficult for him to face a second trial".

The lawyer said that Judge Margarida Alves – who presided over Pinto's first trial - had noted that; "we cannot forget his contribution, his contribution to reveal facts which have been at the origin of main criminal investigations all over Europe… to open the eyes of humanity, of Europe citizens and what's going on under the magnificent wall of [the] football industry."

However, she also told the court in Lisbon: "The freedom to inform does not justify violations of privacy." She added: "The court has no doubt... It has clearly been established that he was hoping to get money.”

In 2023, as a separate trial in Paris, Pinto also received a six-month suspended sentence after admitting to illegally accessing confidential information on PSG.