It's no longer full steam ahead for Google's acquisition of fitness tracking company, Fitbit. The European Commission launched an in-depth antitrust investigation, expressing concern that the takeover would further strengthen Google's market position in online advertising and increase of data collection from consumers, according to a report by CNN.

Google announced it was acquiring Fitbit in November 2019, in what was one of the largest acquisitions for the company, worth $2.1 billion. The deal provided an opening for the company to become involved with wearable devices such as fitness trackers and smartwatches.

The EU previously launched a preliminary investigation into the deal, but Margrethe Vestager, the top antitrust official for the EU, said that the use of wearable devices by European consumers and the amount and depth of the data generated by them is expected to grow significantly, and a commitment by Google not to use Fitbit data for advertising purposes was insufficient, prompting the current investigation.

"Our investigation aims to ensure that control by Google over data collected through wearable devices as a result of the transaction does not distort competition," Vestager said.

Google has already been hit with several fines in Europe for breaching EU's competition law.

Rick Osterloh, Google's senior vice president for devices and services said in a recent blog post that the deal was about devices, not data and claims that Google never intended to use Fitbit's information for Google ads. According to Osterloh, Google is planning to work with the EU on "an approach that addresses consumers' expectations of their wearable devices."

The EU investigation will last four months.