The top attorney for the state of Texas on Wednesday revealed a list of demands for inside information intended to ferret out whether Google abused its power in the online search ad arena.
Texas attorney general Greg Abbott wanted names of people responsible for Google ads, search results, and business relations along with internal documents and minutes from meetings at the California firm.
The "civil investigative demand" paperwork dated July 29 of last year stated the intent was to investigate "the possibility of monopolization in the market for Internet search advertising."
Abbott's office would not discuss whether Google had complied with the demands.
"We're continuing to work with the Texas attorney general's office to answer their questions and understand any concerns," Google said in an email response to an AFP inquiry.
"Since we started Google we have worked hard to do the right thing by our users and our industry, and while there's always going to be room for improvement, we're committed to competing fair and square."
Google is focused on delivering the most relevant results and ads to users, said deputy counsel Don Harrison who disclosed Abbott's antitrust inquiry more than five months ago in a blog post.
"Our focus is on users, not websites," Harrison said.
"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."
The more than 50 requests itemized on three pages included any documents related to the manual override of search results generated by Google's automated algorithm, as well as the blacklisting of any websites.
Google's dominance of the multi-billion-dollar online search market has put it in crosshairs of regulators concerned it might abuse its position.
The US Justice Department is reportedly considering a court challenge to Google's $700 million acquisition of travel information company ITA Software.
Federal antitrust lawyers were said to be examining whether acquiring ITA, which powers many of the Web's most popular travel sites, would give the Internet search giant too much sway over the online travel industry.
Online travel firms have urged the US authorities to block the deal.
ITA, a 500-person firm based in Cambridge, Massachusetts, specializes in organizing airline data, including flight times, availability and prices.
Its QPX flight data organization tool uses algorithms to combine flight information from airlines, including pricing and availability, to create a searchable database.
QPX software is used by online travel agencies and airlines. Microsoft's Bing search engine, Kayak, Orbitz and TripAdvisor are ITA customers.
Italy's antitrust authority in January closed a probe into Google for alleged abuse of its market position, saying it accepted pledges made by the search engine to provide greater transparency.
European Union regulators in November launched a full-frontal attack on Google, formally opening an antitrust probe after rivals accused the Silicon Valley giant of rigging the online search market.
Smaller companies accused Google of "unfavorable treatment" of their services in both unpaid and sponsored search results, the crucial listings that make the Web navigable.
Explore further: UN moves to strengthen digital privacy (Update)