An investigation report was published by Wall Street Journal on Friday, which said that Google has been manipulating search results.

After conducting more than 100 interviews and testing the tech giant's algorithm, the Journal revealed that Google has been interfering the search results by making algorithmic changes prioritizing big businesses, such as its major advertiser eBay, over smaller companies.

Major websites, such as Amazon and Facebook, are also among those that benefited, according to people familiar with the matter.

The report indicates that Google made about 500 changes to its algorithms back in 2010, and the number increased to 3,200 in 2018.

In a statement to CNBC, Google disagreed: "We have been very public and transparent around the topics covered in this article, such as our Search rater guidelines, our policies for special features in Search like Autocomplete and valid legal removals, our work to combat misinformation through Project Owl and the fact that the changes we make to Search are aimed at benefiting users, not commercial relationships."

The search engine giant has been blacklisting certain spam sites including those featuring child abuse or copyright infringement, to prevent others from surfacing in certain types of results, said the report.

Co-founders Larry Page and Sergey Brin, have disagreed on how much to intervene on search results and to what extent: Brin argued against human intervention while Page encouraged more interventions, according to people familiar with the matter.

"Employees can push for revisions in specific search results, including on topics such as vaccinations and autism," said the report.

Google said in the statement to CNBC that the WSJ article contains "a number of old, incomplete anecdotes, many of which not only predated our current processes and policies but also give a very inaccurate impression of how we approach building and improving Search."

"We take a responsible and principled approach to making changes, including a rigorous evaluation process before launching any change - something we started implementing more than a decade ago," the tech giant added.