Russian operatives spent tens of thousands of dollars to run advertisements on Google's various platforms intended to affect the 2016 US presidential election, according to a new report from The Washington Post.

Facebook has come under heavy criticism in recent weeks after it said that Russian agents had paid for ads to spread political division in the contentious election, and Twitter has also banned more than 200 accounts linked to a Russian propaganda unit.

But the new revelation illustrates that the Russian propaganda campaign may have been even wider still.

According to The Post, the Google ads tried to "spread disinformation" and were a multipronged approach. They appeared on Google Search as well as on Gmail, YouTube, and DoubleClick ads.

The total ad spend by "Russian agents" identified was reportedly less than $100,000, and it's unclear whether some came from "legitimate Russian accounts." It's not clear how many ads there were or how many times they were clicked on.

And on Sunday, The Daily Beast reported that Russia recruited YouTubers to "bash" Hillary Clinton, highlighting a pro-Donald Trump YouTube channel that it says was backed by the Russian government and was previously banned from Facebook and YouTube.

Google did not immediately respond to Business Insider's request for comment.

Facebook found roughly 3,000 ads adverts linked to Russia -- but it has refused to publicly release them despite calls from congressional investigators. It cited the investigation led by the special counsel Robert Mueller as hindering it from releasing the ads, Business Insider previously reported.

In a blog post in September, Facebook's chief security officer said the "ads and accounts appeared to focus on amplifying divisive social and political messages across the ideological spectrum."

The vice chairman of the Senate Intelligence Committee, Mark Warner, has said he thinks Russian-linked accounts' purchase of $100,000 worth of Facebook ads is only "the tip of the iceberg."

On November 1, Facebook, Twitter, and Google will testify in a public hearing about Russian activity on social media and political advertising.

This post originally appeared on Business Insider.