Manchester City have been handed a two-year ban from European football and a £24.9m fine for breaching UEFA's Financial Fair Play and club licensing regulations.
The Premier League champions are not permitted to compete in any UEFA competitions for the 2021/22 and 2022/23 seasons after an Adjudicatory Chamber of the Club Financial Control Body (CFCB) found the City guilty of "serious breaches" of the aforementioned regulations.
City have been found guilty of overstating sponsorship revenue and break-even information in accounts submitted to UEFA between 2012 and 2016.
German magazine Der Spiegel published a series of articles in 2018 which accused City of using illegal methods to circumnavigate Financial Fair Play's rules.
Last March, UEFA launched a formal investigation into the accusations. The Premier League is still conducting its own investigation, and won't be making any immediate comment on UEFA's ruling.
The English champions intend to appeal against the sanctions to the Court of Arbitration for Sport.
If the decision is upheld, the team that finishes fifth in the Premier League will enter the Champions League in City's stead should Pep Guardiola's men finish in the top four as expected.
"Manchester City is disappointed but not surprised by today's announcement by the UEFA Adjudicatory Chamber," a club statement read.
"The club has always anticipated the ultimate need to seek out an independent body and process to impartially consider the comprehensive body of irrefutable evidence in support of its position.
"In December 2018, the UEFA Chief Investigator publicly previewed the outcome and sanction he intended to be delivered to Manchester City, before any investigation had even begun. The subsequent flawed and consistently leaked UEFA process he oversaw has meant that there was little doubt in the result that he would deliver. The club has formally complained to the UEFA Disciplinary body, a complaint which was validated by a CAS ruling.
"Simply put, this is a case initiated by UEFA, prosecuted by UEFA and judged by UEFA. With this prejudicial process now over, the club will pursue an impartial judgement as quickly as possible and will therefore, in the first instance, commence proceedings with the Court of Arbitration for Sport at the earliest opportunity."
News of City's ban will generate speculation over the future of Guardiola, who has made no secret of his desire to win the Champions League again.
The ban may also make it difficult for the Manchester club to hold on to some of their big players, who now face the prospect of missing out on two seasons of European football.