A former Competition and Markets Authority official has filed a £2 billion ($2.7 billion) lawsuit against Apple on behalf of app developers, Reuters reports. The suit claims Apple's App Tracking Transparency policy imposed stricter rules on third-party developers than on Apple's own services, giving the company's advertising ecosystem an unfair advantage.

Apple told Reuters it was "bound by the exact same requirements as all developers." However, regulators across Europe, including in France, Italy, and Poland, have investigated ATT. Germany's Federal Cartel Office determined last month that Apple favored its own apps over external developers, noting ATT pop-ups encouraged consent for Apple services while discouraging it for third-party apps.

Apple agreed to change how ATT works in the European Union. This follows the French Competition Authority fining Apple €150 million ($175 million) over ATT last year.