Montana Senator Jon Tester has called on Senate Homeland Security Committee Chairman Ron Johnson to launch a full investigation into the Russian interference in the U.S. presidential election.

In a letter to Chairman Johnson, Tester outlined the need for an investigation into Russian President Vladimir Putin, and laid out evidence of the Russian government’s actions to interfere with the election.

“It has been firmly established that Russian President Vladimir Putin and the Russian government unleashed a pervasive influence campaign in the United States designed to sway our recent election.” Tester wrote.  “Only a thorough, transparent investigation will allow the American people to learn exactly what transpired during the 2016 presidential campaign and what changes, if any, are necessary to safeguard our nation’s critical infrastructure from further hacking.”

Tester was joined by six other members of the Senate Homeland Security Committee in calling on Chairman Johnson to launch an investigation.  The Senate Homeland Security Committee has oversight jurisdiction over the country’s election infrastructure.

Tester’s letter highlights evidence of Russian interference in our election, and points to a report released by the Office of the Director of National Intelligence that states, “Russian President Vladimir Putin ordered an influence campaign in 2016 aimed at the U.S. presidential election.”

Tester’s letter to Chairman Johnson comes days after he called for a bipartisan Select Committee to investigate Russia’s influence on Trump Administration officials—including former National Security Adviser Michael Flynn.

Flynn resigned earlier this week after reports surfaced that he had engaged in unauthorized communication with Russian Ambassador to the United States, Sergey Kislyak.

A copy of Tester’s letter is available HERE.