Tech companies such as Facebook, Google and Twitter did "the bare minimum" to comply with the Senate Intelligence Committee's investigation into Russian misinformation on their platforms, according to two new third-party reports compiled for the committee. The reports were released Monday.

The reports, commissioned by the Senate Select Committee on Intelligence, were conducted by two separate third-party research teams. One report was compiled by the cybersecurity company New Knowledge alongside researchers at Columbia University and Canfield Research LLC, while another was conducted by researchers at the University of Oxford in collaboration with the social media analysis company Graphika. The wide-ranging reports outline how Russian actors used social media platforms to spread divisive content in the lead-up and aftermath of the 2016 U.S. election.

Once it became clear that social media platforms played a key role in the election, researchers from both reports said, tech companies did as little as they could to comply with researchers' requests. These companies may even have removed key metadata from the information they submitted to researchers, the New Knowledge report alleges.

Facebook did not provide any account data to New Knowledge, and Twitter provided only shortened links, rather than data on full URLs, the report claims. Facebook submitted only organic post data from select Pages in English, the Oxford-Graphika report says, and chose not to disclose information in other languages or from Profiles and Groups created by Internet Research Agency, a business owned by a person with close ties to Russian President Vladimir Putin.

In a statement, a Facebook spokesperson said, "As we've said all along, Congress and the intelligence community are best placed to use the information we and others provide to determine the political motivations of actors like the Internet Research Agency. We continue to fully cooperate with officials investigating the IRA's activity on Facebook and Instagram around the 2016 election. We've provided thousands of ads and pieces of content to the Senate Select Committee on Intelligence for review and shared information with the public about what we found. Since then, we've made progress in helping prevent interference on our platforms during elections, strengthened our policies against voter suppression ahead of the 2018 midterms, and funded independent research on the impact of social media on democracy."

Google made it harder for researchers to analyze its data by submitting IRA-purchased ads in image or PDF format, rather than in a machine-readable file, the Oxford-Graphika report says. Researchers claim Google should have easily been able to submit the files in a way that would be easier to analyze since the files it submitted had information "previously organized in spreadsheets."

"Google's data contribution was by far the most limited in context and least comprehensive of the three," the researchers said, noting Google did not disclose account data on its ads, Google+ or YouTube. Google declined to comment, but pointed CNBC to its previous blog posts on political ad transparency and stopping the spread of misinformation.

Of all the companies, Twitter provided the greatest amount of data in response to the request, according to the Oxford-Graphika report.

"The average monthly Twitter post volume is over fifty thousand tweets per month, while the average monthly volume of Facebook ads, Facebook posts and Instagram posts is in the hundreds to low thousands, never exceeding the six thousand mark," according to the report.

In a statement, a Twitter spokesperson said, "Our singular focus is to improve the health of the public conversation on our platform, and protecting the integrity of elections is an important aspect of that mission. We've made significant strides since 2016 to counter manipulation of our service, including our release of additional data in October related to previously disclosed activities to enable further independent academic research and investigation."

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