Story highlights It calls Snowden's activities the "largest and most damaging public release of classified information" in history

Two-year investigation comes as some are calling for Obama to pardon Snowden

Washington (CNN) Edward Snowden has been in contact with Russian intelligence officials since arriving in Russia in 2013, according to a new report from Congress.

"Since Snowden's arrival in Moscow, he has had, and continues to have, contact with Russian intelligence services," the 33-page report, issued Thursday by the bipartisan House Permanent Select Committee on Intelligence, said.

Snowden, the former National Security Agency contractor who leaked volumes of information on American intelligence and surveillance operations to the media, settled in Moscow after initially traveling to Hong Kong following his 2013 public disclosure of classified information. The Russian government granted asylum to Snowden shortly thereafter.

Large portions of the pertinent section, entitled "foreign influence," are redacted, but one paragraph reveals the Russian link, saying that Frants Klintsevich, the deputy chairman of the Russian parliament's defense and security committee, "publicly conceded that 'Snowden did share intelligence' with his government."

Snowden immediately took to Twitter following the report's release to dispute the accusations, writing "they claim without evidence that I'm in cahoots with the Russians."

Despite this, they claim without evidence I'm in cahoots with Russian intel. Everyone knows this is false, but let's examine their basis: — Edward Snowden (@Snowden) December 22, 2016

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