The European Union's antitrust regulatory body has launched a two-pronged complaint against US tech giant Apple, claiming that its App Store and Apple Pay platforms are operating unfairly and possibly going against existing antitrust laws. The EU's antitrust head, Margrethe Vesteger, has questioned the company's market power and how it may be unfairly pushing out rivals and squeezing app developers out of their rightful earnings.

The new complaint comes just four years after Apple was hit with a record-breaking tax bill by the EU regulator. Now, Vesteger is shifting her focus on Apple's other mobile platforms.

According to the complaint, the regulator believes that Apple's App Store may be in violation of the trading bloc's competition laws given how it requires all developers on its platform to give up 30 percent of their sales as commission. The regulator is also reviewing Apple's "tap-and-go" practice on its Apple Pay platform.

In a statement released on Tuesday, Vesteger stated that Apple's self-serving role as the gatekeeper of all apps and content for users of its mobile ecosystem could distort competition within its platform. She added that Apple is unfairly competing with other developers with its own apps, such as Apple Music and Apple Books, which are not subject to its 30 percent cut.

Due to the practice, the regulator has launched a new probe into Apple's business. The probe is the latest one launched by the EU against US-based tech giants. Last year, the regulator concluded its decades-long inquiry into Google's business, resulting in a massive $9 billion fine that was slapped on the search engine giant. The EU regulator has also launched a separate investigation into Amazon, which is expected to escalate in the coming weeks.

In response to the new complaint, Apple claims that the EU is merely responding to some app developers that want to hitch a free ride on its platform. The Cupertino-based giant added that it is disappointed with the EU's decision to act on "baseless complaints." Apple clarified that its goal is simply to provide a safe and secure platform so its users can have access to the very best apps and content available. Apple said that it welcomes competition on its platform and its system has so far resulted in more than $120 billion worth of sales for developers using its App Store.

Apple is currently still at odds with the EU regulator, recently filing an appeal to its 2016 order for it to pay 13 billion euros or $14.7 billion in unpaid taxes to Ireland. Apple previously claimed that Vestager's actions were politically motivated and part of the bloc's aim of taxing digital giants in Europe.