By Josh Ong

Published: 01:00 AM EST (10:00 PM PST)

In the wake of a recent controversy surrounding Google's decision to feature Google+ content in its search results, the company will face scrutiny of its social networking service from the U.S. Federal Trade Commission as part of an antitrust probe, a new report claims.

Two people familiar with the situation have alerted Bloomberg to the federal agency's plan to include Google+ in the investigation. At issue is the possibility that Google violated antitrust laws if it gave preference to its own services on its search engine, the sources said.

The alleged expansion to the FTC's probe comes on the same week that Google attracted harsh criticism for its new "Search, plus Your World" feature. The Mountain View, Calif., company announced on Tuesday that it would begin including personalized results tailored to users' Google+ profiles and serving up "related people and pages" from its Google+ service.

The changes were met with widespread disapproval after it was revealed that empty Google+ pages were displacing apparently more relevant results from rivals Facebook and Twitter. Search Engine Land's Danny Sullivan published a series of posts detailing the changes and possible implications.

Twitter quickly spoke up in opposition to the changes, claiming that the new results are "bad for people, publishers, news organizations" and its own users.

Google fired back on Google+ that it was "surprised" by Twitter's comments because the company chose not to renew its agreement with the search giant. However, some pundits have suggested that the agreement between Twitter and Google broke up because of differences over money.

“We believe that our improvements to search will benefit consumers,” Google spokesman Adam Kovacevich told Bloomberg over email. “The laws are designed to help consumers benefit from innovation, not to help competitors.”

Google Chairman Eric Schmidt said earlier this week that he doesn't believe Google is favoring itself by suggesting Google+ pages. He also indicated that he was willing to talk to Facebook and Twitter about including them in the results.

Meanwhile, some groups, such as the Electronic Privacy Information Center have begun calling for the FTC to look into Google' s changes and "business practices," the report noted.

Google confirmed last June that the FTC was conducting a review of its business and stated it would work with them to answer its questions. Sources have claimed that the FTC is looking into whether Google is preventing smartphone manufacturers from using competitors' services on its Android operating system and allegations that it down-ranked rival websites while harvesting their data.

The company has also been on the hot seat recently over several troubling violations of its own informal "Don't be evil" motto. Earlier this month, it came to light that some blog posts that claimed to be "sponsored by Google" were violating the company's own guidelines against paid links. Google quickly disavowed the links as a mistake made by bloggers working with third-party advertising firm Unruly Media, which had been hired by Google to promote its Chrome browser. The company then punished itself by down-ranking its Chrome website for at least 60 days.

More recently, Kenyan business listings company Mocality released evidence that Google appeared to have been "systematically accessing Mocality’s database and attempting to sell their competing product to our business owners." Recordings revealed Google representatives falsely claiming to have partnered with Mocality.

Google quickly responded that it was "mortified to learn that a team of people working on a Google project improperly used Mocality’s data and misrepresented [its] relationship with Mocality to encourage customers to create new websites." The company "unreservedly apologized" to Mocality and promised to take the "appropriate action with the people involved" after looking into the mater.