The FTC is investigating Google over anti-competitive practices in South Korea, more specifically, they're being investigated over whether or not they interfered in any way with Samsung's OS development within the country. Samsung is one of Google's largest Android partners and has the biggest and most popular lineup of devices running on the platform. Samsung also has their own operating system, though it's not really found on many phones and never really reached mainstream popularity. It's now been revealed that the Fair Trade Commission opened up an investigation into the Anti-Fragmentation Agreement in May of 2016, an agreement made in 2011 between Samsung and Google in which Samsung agreed with Google to not develop an operating system that used Google's algorithms in any way.
According to the report, the investigation that started last year is said to have uncovered what is being referred to as suspicious circumstances that point to Google potentially obstructing Samsung's development of an operating system. It isn't mentioned specifically what the operating system is, so there's no detail regarding whether this was in relation to Tizen or not, though it might be suspected as such by some as Tizen is the OS that Samsung currently uses for some of their products and they haven't been able to reach mainstream popularity with it on smartphones.
Perhaps partly due to the nature of the FTC's findings last Spring, the FTC has stated that they may reopen a case against Google from 2013 which was in complaint about Google's Mobile Application Distribution Agreement, another agreement which was from 2011 and the same time as the AFA that is now being investigated by the FTC. The report states that the FTC is looking into whether or not it can reopen the case for investigation as it's been requested from lawmakers that they do so, which means that while the investigation may be reopened, it's also possible that it may not be. This new investigation is the most recent issue that Google is facing over anti-competitive claims, with the search company having been dealing with the EU over anti-competitive practices since last year about the company's search dominance.