The European Commission (EC) decided to formally investigate allegations Apple gives preferential treatment to its own music service, following a complaint from Spotify, Financial Times (FT) reported.

Its decision was reportedly made after discussions with customers, competitors and other market participants, with the probe set to commence in the coming weeks.

Spotify lodged a complaint with the EC in March, accusing Apple of implementing harmful App Store policies and giving its own music service an “unfair advantage at every turn”. Apple hit back, insisting “everyone is playing by the same set of rules” and alleging Spotify wanted to reap the benefits of the App Store ecosystem “without making any contributions to that marketplace”.

EC competition commissioner Margrethe Vestager previously said it was considering a probe.

Apple could face hefty fines if Spotify’s claims are upheld: US tech giant Google has been fined a total of more than €8 billion from three separate EC investigations in recent years, notably a €4.3 billion penalty for forcing device makers using its Android operating system to install Google apps; and another €2.42 billion for using its search engine to promote its shopping service over rivals.

The EC recently declined to open an investigation into whether Apple was hindering mobile payment rivals in favour of Apple Pay, finding it is not a dominant force in the market.

News of the music player probe comes ahead of Apple’s World Wide Developer’s Conference, set to start on 3 June, at which the company is expected to showcase updates to its iPhone operating system and core apps.