The late Sen. John McCain John Sidney McCainAnalysis: Biden victory, Democratic sweep would bring biggest boost to economy The Memo: Trump's strengths complicate election picture Mark Kelly: Arizona Senate race winner should be sworn in 'promptly' MORE (R-Ariz.) expressed alarm about Russia's interference in the 2016 elections in an upcoming documentary.

"The fact that there was an attack on the fundamental — the absolute fundamental — a free and fair election, should alarm all of us,” McCain says in a clip posted by posted by the Daily Beast on Thursday.

ADVERTISEMENT

The Daily Beast said McCain's comments were referring to reports from August 2016 that Russian hackers had infiltrated voter databases in U.S. states, including McCain's home state of Arizona.

McCain died on Saturday a little more than a year after being diagnosed with brain cancer. His clips throughout the film appear to have been filmed before Trump's July summit with Putin, according to the Daily Beast.

McCain, an outspoken Russia hawk, denounced Trump's meeting with Putin as "one of the most disgraceful performances by an American president."

"As long as people can do things without penalty, they’re going to continue to do them," McCain says in another clip from the film.

The former Senate "maverick" is joined by former Democratic presidential nominee Hillary Clinton Hillary Diane Rodham ClintonFox News poll: Biden ahead of Trump in Nevada, Pennsylvania and Ohio Trump, Biden court Black business owners in final election sprint The power of incumbency: How Trump is using the Oval Office to win reelection MORE and former U.S. Ambassador to Russia Michael McFaul in the documentary, "Active Measures," from director Jack Bryan, which is due to be released on Aug. 31.

Bryan told the Daily Beast by email that he asked McCain to participate in the film because "he was one of the few voices in his party who refused to remain silent" about Russian interference.

“In 2004 when Putin tried to rig an election in Ukraine, John McCain stood with the Ukrainian people," Bryan wrote. "In 2016 when Putin tried to do the same thing in America, he was one of the few voices in his party who refused to remain silent."

“He and Hillary Clinton were Vladimir Putin's greatest adversaries in the United States, and without their voices it would be impossible to understand how and why our country arrived at this point,” Bryan added.

The filmmaker called McCain "the most forceful voice in Congress at speaking out against Russian aggression and standing up for democracy worldwide.”

The Daily Beast reports that the film focuses mainly on Trump's connections with Russia, including his long-standing business ties.