The body told Reuters it started preliminary investigations into how both companies handle data. "These investigations concern the way data is gathered, processed, used and monetized including for advertising purposes," the EU's competition watchdog said.

Regulators are hoping to determine whether Facebook places restrictions on data use by third-party companies in exchange for access to APIs for its core platform and Instagram. They're attempting to find out if Facebook hampers access to data and if so, why. Engadget has contacted the company for comment.

EU officials are said to be concerned over the vast troves of data major tech companies store and whether they use such information to hamper competitors. Last month, it emerged EU regulators are looking into Facebook's Marketplace service related to how the classified ads market has changed over the last few years and the commercial links between the company and its rivals.