Google was in the EU antitrust spotlight again on Tuesday as regulators opened an investigation into whether its digital advertising business gives the Alphabet unit an unfair advantage over rivals and advertisers, Reuters reported from Brussels.

“The formal investigation will notably examine whether Google is distorting competition by restricting access by third parties to user data for advertising purposes on websites and apps while reserving such data for its use,” an ANI news dispatch quoted European Union as saying.

It also added that the investigation will focus on display advertising where Google offers several services both to advertisers and publishers.

Executive Vice-President Margrethe Vestager, in charge of competition policy, said, “We are concerned that Google has made it harder for rival online advertising services to compete in the so-called ad tech stack. A level playing field is of the essence for everyone in the supply chain. Fair competition is important- both for advertisers to reach consumers on publishers’ sites and for publishers to sell their space to advertisers, to generate revenues and funding for content. We will also be looking at Google’s policies on user tracking to make sure they are in line with fair competition.”

The EU investigation will look into Google’s plans to block some user-tracking technologies in the Chrome browser and on Android smart mobile devices.

It will also examine Google’s advertising practices on YouTube and other policies concerning Google Ads.