Google has blamed a coding bug for burying search results for TripAdvisor and Yelp.
Executive from the two sites, which compete with Google to offer travel and business recommendations, tweeted examples of smartphone searches over the weekend that included their company names but pointed people toward Google's reviews and maps results.
"Gimme a break, @google. Search for 'tripadvisor hilton' puts the tripadvisor link so far down you can't see it," TripAdvisor Chief Executive Stephen Kaufer tweeted.
"Wonder if teens think this is Yelp," Yelp Chief Executive Jeremy Stoppelman tweeted, posting a picture of a Google listing that popped up when he searched for Yelp and the name of a restaurant.
Google pinned the distorted results on a flaw in its code. "The issues cited were caused by a recent code push, which we're working quickly to fix," the company said in a statement sent Wednesday to CNET.
Companies that rely on Google to drive traffic to their sites argue that the search engine should never manipulate listings and instead should act solely as a neutral platform. If Google uses search results to promote its own services over those of competitors, rivals argue, it destroys competition and misleads consumers.
Such complaints are the basis of a years-long investigation by European competition watchdogs. Both TripAdvisor and Yelp are complainants in the inquiry. Google has also come under fire repeatedly in the US for allegedly prioritizing its own services in search results listings, including on smartphones.
Google denies all such allegations and protests that its search results are driven only by the needs of users. The company has, however, failed on multiple occasions to satisfy requests made by courts and regulatory authorities to do more and provide proof that is actively separating its own services from its search tool.
Stoppelman expressed doubt that the search issues affecting Yelp were caused by a bug and suggested that Google was targeting the company. "Google sounding about as truthful as Trump, web search becoming a dirty business of burying your competition," he tweeted Tuesday.
Travis Katz, chief executive of travel site Gogobot, lent his support of Stoppelman's skepticism.
"Google not burying Gogobot or 4sq [FourSquare] for same queries, making it unlikely this is a bug," he tweeted. Responding to a question from one Twitter user asking whether his company was part of any antitrust suit against Google, Katz responded: "Gogobot is not involved directly, yet."
Update, 9 a.m. PT: Google's statement to CNET has been added.