Texas Attorney General Greg Abbot has launched an anti-trust probe into Google.
The probe will determine exactly how the company's website ranking system works.
The move comes after complaints from three web companies, myTriggers, SourceTool and Foundem, which have claimed that Google has deliberately reduced their web traffic by ranking them lower on the search engine, news agency the Associated Press reports.
"Given that not every website can be at the top of the results, or even appear on the first page of our results, it’s unsurprising that some less relevant, lower quality websites will be unhappy with their ranking,” Google's deputy general counsel, Don Harrison, wrote in a blogpost.
Harrison said that the company is looking forward for cooperating with the Attorney General's office, saying that he is confident that the company "operates in the best interests of our users".
A spokesperson for the Texas Attorney General's office confirmed the investigation, but has refused to reveal further details.