The owner of the Daily Mail newspaper and MailOnline website is suing Google over allegations the search engine manipulates search results.
Associated Newspapers accuses Google of having too much control over online advertising and of downgrading links to its stories, favouring other outlets.
It alleges Google "punishes" publishers in its rankings if they don't sell enough advertising space in its marketplace.
Google called the claims "meritless".
Associated Newspapers' concerns stem from its assessment that its coverage of the Royal Family in 2021 has been downplayed in search results.
For example, it claims that British users searching for broadcaster Piers Morgan's comments on the Duchess of Sussex following an interview with Oprah Winfrey were more likely to see articles about Morgan produced by smaller, regional outlets.
That is despite the Daily Mail writing multiple stories a day about his comments around that time and employing him as a columnist.
Daily Mail editor emeritus Peter Wright told the BBC's Today programme that the search engine's alleged actions were "anti-competitive".
He suggested that the Daily Mail's search visibility dropped after using online advertising techniques "which were allowing us to divert advertising traffic away from Google to other ad exchanges, which paid better prices - and this was their punishment".
"We think it's time to call this company out," he said.
The Daily Mail's MailOnline site is one of the world's most-read websites. It has 75 million unique monthly visitors in the US alone, according to the lawsuit, which was filed in New York on Tuesday.
A Google spokeswoman said: "The Daily Mail's claims are completely inaccurate.
"The use of our ad tech tools has no bearing on how a publisher's website ranks in Google search.
"More generally, we compete in a crowded and competitive ad tech space where publishers have and exercise multiple options. The Daily Mail itself authorises dozens of ad tech companies to sell and manage their ad space, including Amazon, Verizon and more. We will defend ourselves against these meritless claims."
Separately, Google is facing antitrust lawsuits brought by the US Justice Department and attorneys general in several states.
The technology giant has denied abusing its market power and has previously said the ad technology market is competitive.