Russian agents spent tens of thousands of dollars on ads that were part of a campaign of misinformation and were posted on various Google services, including YouTube and Google's search engine, The Washington Post reported.
The newspaper added that the technology giant revealed the disinformation campaign backed by the Russians as it weighs whether it will testify before Congress next month. Social networking companies Facebook and Twitter have already agreed to testify.
The Washington Post reported that Google is still in the early stages of its research.
The newspaper report says the company discovered the Russian presence when analyzing Twitter data. The Washington Post report cites anonymous sources familiar with the internal research.
In a statement, Google said it has a set of strict advertising policies that include limits on targeted advertising policy and bans on approaches based on race and religion.
"We are deepening research on attempts to abuse our systems, working with researchers and other companies, and will provide assistance to ongoing investigations".
Facebook recently shared with Congress about 3,000 ads sponsored by Russia.
US intelligence officials concluded that the government of Russian President Vladimir Putin led a campaign of misinformation aimed at helping Donald Trump win the last year presidential election.