A representative from Google denied to Sen. Marsha Blackburn (R-TN) that the company operates search blacklists during a Senate hearing today, despite the fact that leaked emails published by Breitbart News have exposed the tech giant for doing exactly that.

In response to a line of questioning from Sen. Marsha Blackburn (R-TN), Google VP for government affairs and public policy Karan Bhatia denied that the company, which also owns YouTube, uses blacklists.

“We don’t use blacklists [or] whitelists to influence our search results,” said Bhatia.

A few seconds later, he reiterated his response.

“As I said, per your previous question, we do not utilize blacklists or whitelists in our search results to favor political outcomes … that’s not — doesn’t happen.”

Yet just a few months ago, in January, Breitbart News published internal discussions from Google proving that YouTube, the video hosting platform owned and operated by Google, maintains a file called “youtube_controversial_query_blacklist.” When a search term is added to the file, it causes the top search results on YouTube to be restricted to pre-approved “authoritative” videos, usually from left-leaning and mainstream media outlets.

According to the discussion published by Breitbart News, blacklisting isn’t an uncommon activity at Google:

In the leaked discussion thread, a Google site reliability engineer hinted at the existence of more search blacklists, according to the source. “We have tons of white- and blacklists that humans manually curate,” said the employee. “Hopefully this isn’t surprising or particularly controversial.”

Employees at the company have added all manner of politically charged search terms to the list, including “abortion,” “David Hogg,” and “Maxine Waters.” Project Veritas also revealed that Google added over a hundred search terms related to the referendum to decriminalize abortion in Ireland, shortly before the vote.

Breitbart News also published an email from Google’s “Trust and Safety” team admitting that the company also, on rare occasions, intervenes in its organic search results.

“The bar for changing classifiers or manual actions on span in organic search is extremely high,” wrote the employee. Organic search refers to Google’s search engine, so blacklisting isn’t limited to Google’s YouTube subsidiary.

Psychologist and search engine expert Dr. Robert Epstein, who also spoke at the hearing, has said that Google operates “at least nine blacklists that impact our lives, generally without input or authority from any outside advisory group.”

The Daily Caller also reported that Google has a de facto blacklist of conservative news sites, including Conservative Tribune and the Gateway Pundit, which do not appear in its news search results.

Are you a source at YouTube or any other corporation who wants to confidentially blow the whistle on wrongdoing or political bias at your company? Reach out to Allum Bokhari securely at allumbokhari@protonmail.com.

Allum Bokhari is the senior technology correspondent at Breitbart News.