Google looks set to be subject to an investigation by the Federal Trade Commission (FTC) in the US.
According to the Wall Street Journal, the FTC is expected to launch the investigation , which will look at whether Google's search results steer web users to the firms service rather that those from rival companies, in the next few days.
A number of web firms claim Google's procedure of placing its own services in its 'natural' search results, means it can unfairly dominant the market.
"Google engages in anticompetitive behaviour...that harms consumers by restricting the ability of other companies to compete to put the best products and services in front of internet users, who should be allowed to pick winners and losers online, not Google," Fairsearch.org, a group representing several firms, including Microsoft and travel website Expedia, told the WSJ.
This isn't the only antitrust investigation against Google, which has yet to comment on the matter.
In November, the European Commission launched an investigation after three complainants accused it of demoting rival sites in search results and giving preference to its own services