Allegations that Manchester City artificially inflated commercial agreements with their main sponsor Etihad were "not established to the comfortable satisfaction" of the Court of Arbitration for Sport (CAS), which also concluded the Premier League club showed a "blatant disregard" for UEFA's Financial Fair Play (FFP) investigation principles.
City had a two-season ban from UEFA competitions quashed earlier this month after CAS found they were not guilty of "disguising equity funds as sponsorship contributions", although they were fined €10 million (A$16m) for not co-operating with the investigation launched by European football's governing body.
UEFA, which previously punished City for FFP violations in May 2014, opened a fresh probe on the back of a series of articles published by German publication Der Spiegel in November 2018, which drew upon information purportedly obtained by the whistleblower Football Leaks.
On Tuesday, CAS released its full arbitral award on the case, which explained those emails were admissible evidence.
However, the allegation that sponsorship money from Etihad - the Abu Dhabi airline that adorns City's playing shirts and lends its name to the club's stadium and training facility – was funnelled in via the Abu Dhabi United Group and Sheikh Mansour's personal fortune could not be proven.
"There is no doubt that Etihad fully complied with its payment towards MCFC and that MCFC rendered the contractually agreed services to Etihad in return," the CAS verdict read.
"The majority of the panel finds that Etihad Sponsorship Agreements are presumed to be negotiated at fair value and that MCFC, HHSM [Mansour], ADUG and Etihad are considered not to be "related parties". The Etihad Sponsorship Agreement were legally binding contracts.
"There is no evidence that agreements were backdated or that MCFC otherwise retrospectively tried to cover up any alleged violations following the publication of the leaked emails."
During the period addressed by the investigation, City were entitled to sponsorship fees and bonuses of £220.57m (A$400m).
Similar claims concerning City's arrangements with Abu Dhabi telecommunications company Etisalat were found to be time-barred under UEFA's rules because the alleged offences took place more than five years before the case was referred to the adjudicatory chamber of UEFA's Club Financial Control Board (CFCB) on May 15, 2019.
Despite the relief felt by Pep Guardiola and his club upon learning they would be able to compete in next season's Champions League, CAS said City should be "strongly condemned" for failing to assist UEFA's investigation.
"The majority of the panel finds that MCFC's failure to cooperate with the CFCB's investigation is a severe breach and that MCFC is to be seriously reproached for obstructing the CFCB's investigations," it concluded, adding it hoped the €10m fine would be a "sufficiently strong deterrent" to any other clubs that might contravene the FFP process.
UEFA has come in for criticism in the weeks since the verdict, but the Swiss-based court said it had a "legitimate basis to prosecute" City and did not instigate "frivolous charges".
Indeed, CAS felt the responsibility for the case going so far lay at the door of City and their standoffish approach.
"The new evidence presented by MCFC in the present proceedings before CAS… had an impact on the panel's findings," it said. "The panel cannot put itself in the shoes of the adjudicatory chamber at the time of issuance of the appealed decision, but it finds that the possibility cannot be excluded that the adjudicatory chamber may have reached the same conclusions as the panel in the present proceedings, had such evidence been made available to it.
"The relevance of this is that MCFC may have avoided the appealed decision by already filing such evidence before the CFCB. The appealed decision is therefore not per se wrong, but, at least to a certain extent, is a consequence of MCFC's decision to produce the most relevant evidence at its disposal, only in the present appeal arbitration proceedings before CAS."
City face Real Madrid in the last 16 of the 2019-20 Champions League on August 7, holding a 2-1 advantage over the 13-time European champions from February's first leg at the Santiago Bernabeu.