Story highlights Democrats have been painting Trump as a friend of the Russian government for months

The language in the letter was echoed in a similar letter from Senate Minority Leader Harry Reid

Washington (CNN) A group of high-ranking House Democrats asked the FBI Tuesday to investigate whether Donald Trump's campaign had any "overt and covert" connection to cyberattacks believed to be conducted by Russian government hackers.

The letter from the top ranking Democrats on the Oversight, Judiciary, Foreign Affairs and Homeland Security committees follow a similar missive from Senate Minority Leader Harry Reid, who also asked the FBI to look into any possible link between the campaign and Russian meddling in the US election.

Democrats have been painting Trump as a friend of the Russian government, which has a tense working relationship with the US, for much of the campaign. The drumbeat intensified after the Democratic National Committee was hacked this spring and a trove of internal documents were leaked online. Cybersecurity experts nearly unanimously point to Russian military and intelligence community hackers as the source.

"Serious questions have been raised about overt and covert actions by Trump campaign officials on behalf of Russian interests," they wrote. "It is critical for the American public to know whether those actions may have directly caused or indirectly motivated attacks against Democratic institutions and our fundamental election process."

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