Manchester City's appeal against a Champions League ban for breaching UEFA's Financial Fair Play regulations was registered by the Court of Arbitration for Sport on Thursday, according to a media release.
Sport's highest court offered no further details, but The Associated Press understands the back-to-back Premier League champions are "challenging the legitimacy and haste of the investigation" and therefore looking to block the case.
The English club previously said UEFA moving the case from its investigatory chamber to its judicial branch "ignores a comprehensive body of irrefutable evidence provided by Manchester City."
According to leaked documents published by German outlet Der Spiegel, Manchester City bypassed FFP guidelines - restrictions in place to prevent clubs from spending more than what they earn - by signing overvalued commercial deals with companies connected with the club's Abu Dhabi-based owners.
Manchester City are accused of deceiving UEFA for several years and are understood to have submitted inconsistent answers when questioned during European football's governing body's investigatory phase.