Google is facing an anti-competitive investigation into whether it obstructed Samsung Electronics' development of its own operating system (OS), which could eventually replace the Android OS.

The Korean Fair Trade Commission (FTC) is checking whether Google thwarted competition in the OS market, and has submitted relevant documents to Rep. Jeon Hae-cheol of the main opposition Democratic Party of Korea (DPK).

The market share for Android in Korea's mobile market accounts for more than 80 percent.

In 2011, the Google and Samsung struck the Mobile Application Distribution Agreement (MADA) that required Android handsets to preset Google as a default search engine and preinstall its applications and services such as YouTube and Gmail on their home screens.

In addition, they also reached the anti-fragmentation agreement (AFA) stipulating that Samsung was not allowed to develop a new OS using Google's algorithms.

At the time, the South Korea's top two search engines Naver and Daum complained about MADA and the FTC investigated Google Korea to see if the preloading requirements violated the Antitrust Law. In 2013, Google was cleared after the antitrust body found the two Korean firms' market shares were not affected.

However, the FTC launched its probe into the AFA last May and found suspicious circumstances hinting at Google's obstruction of Samsung's OS development.

Last August, the Russian government fined Google $6.75 million for competition violations, while the EU reached its preliminary view last April year that the company has, in breach of EU antitrust rules, abused its dominant position by imposing restrictions on Android device manufacturers and mobile network operators.