The former FBI deputy director and his counterpart at the U.K.'s MI5 intelligence agency privately shared concerns about the possible connections between the Brexit vote and Russia's efforts to promote Donald Trump's campaign.
Andrew McCabe, then the second-ranking FBI official, and Jeremy Fleming, the second-ranking British intelligence agency official at the time, exchanged text messages revealing their mutual surprise at the result of the EU referendum that U.S. officials saw as a "wake-up call," reported The Guardian.
A person familiar with the matter told the newspaper that American officials were wary of Russian interference in western elections, but some within the FBI saw the Brexit vote as confirmation that those efforts had been successful.
McCabe and Fleming frequently exchanged text messages starting in June 2016, shortly before the FBI opened its investigation into Trump campaign ties to Russia, but the conversations were cryptic and did not contain specific or sensitive materials, according to The Guardian.
Fleming pointed out in August 2016 that members of the FBI and MI5 had met to discuss "our strange situation," according to the newspaper's source.
The FBI opened a covert counterintelligence investigation -- code name “Crossfire Hurricane” -- on July 31, 2016, to determine whether the Trump campaign had coordinated its efforts with Russia.
That investigation was eventually taken over by Robert Mueller, who found “multiple, systematic efforts to interfere in our election” by Russia, but did not find sufficient evidence to charge Trump campaign associates with conspiracy.
However, the former special counsel found multiple instances where Trump, as president, attempted to obstruct the investigation.
The U.S. and U.K. frequently share intelligence, but McCabe and Fleming appear to seek a more direct line of communication between the two allies about Russian efforts to interfere with their domestic politics.
Fleming appears to make a reference to Peter Strzok, a senior FBI official who traveled to London in August 2016 to meet Australian diplomat Alexander Downer, who reported that Trump campaign adviser George Papadopoulos had told him Russia had campaign dirt on Hillary Clinton.
The U.K. is investigating whether Russia or other foreign actors had made illegal contributions to the Brexit vote in June 2016, and its Electoral Commission found reasonable grounds to suspect possible criminal wrongdoing involving insurance executive and political donor Arron Banks.
Banks has insisted there was “no Russian money, no interference” behind the $9.7 million he gave to the unofficial Brexit campaign.