MANCHESTER, England, (Reuters) – Manchester City will attempt to overturn their two-year UEFA ban from European football when a three-day hearing at the Court of Arbitration for Sport in Switzerland begins today.

European soccer’s governing body UEFA ruled in February that City had committed serious breaches of Financial Fair Play (FFP) regulations and failed to cooperate with its investigation, handing them a ban and a 30 million euro (24.9 million pounds) fine.

UEFA opened an investigation into City last March after the publication of ‘Football Leaks’ documents led to allegations that the club’s Abu Dhabi owners had inflated sponsorship agreements to comply with the FFP requirements.

Reuters was unable to verify if such payments were made well as questioning the nature of the documents, City have been unhappy at the way in which UEFA’s Club Financial Control Body (CFCB) conducted the investigation.

The Abu Dhabi United Group, the investment vehicle owned by Sheikh Mansour bin Zayed Al Nahyan, is the majority owner of the City Football Group, with a stake of around 77%.