Touted by Russia's state broadcaster RT as a geopolitical analyst, a New Yorker was a frequent guest and oft-cited expert in Russian media.
For years, Mr Eric Draitser spoke authoritatively on Russian TV against the United States' "imperialist foreign policy", and accused the Ukrainian government of being its puppet.
But in 2015, Mr Ruslan Deynychenko, co-founder of fact-checking organisation StopFake.org, dug into Mr Draitser's background and proved the so-called expert to be a fake. He was a car insurance salesman, with no academic background or scientific research in geopolitics, Mr Deynychenko said.
"It is disgusting," said the former Ukrainian journalist.
The case is one of thousands that Mr Deynychenko, 46, and the StopFake project encountered since it was established after Ukraine's 2014 revolution, he told The Straits Times in an interview yesterday after speaking before the Select Committee on deliberate online falsehoods.
StopFake was set up at a time when the term "fake news" was no different from Russian propaganda, he said.
He was the first of seven foreign experts invited to speak before the Select Committee and the only one to turn up in person, having flown in from Ukraine the previous day. The others gave their comments and views via video conferencing.
StopFake is staffed by about 30 journalists, academics, IT specialists and translators. It receives funding mainly from the British Embassy in Ukraine, he said.
He believes Russia used sensational news, albeit false, like Ukrainians raping and killing Russians, to gain support for pro-Russian separatists in Ukraine.
Eventually, it led to the Crimea being annexed and the war in eastern Ukraine, with 10,000 people losing their lives, he added.
Evidence from StopFake led to people no longer seeing Russian media organisations as free media, he said. The Ukraine government banned Russian television networks despite other nations arguing that it stifled free speech.
He warned the Select Committee that any country that ignores disinformation risks falling prey to such campaigns without even realising it.
Mr Deynychenko said: "It may happen with any country that one day, you wake up and look out the window and see people with machine guns because somebody on TV persuaded them they should hate each other.
"Our experience demonstrated that disinformation is a powerful weapon, and it could be pointed at any country at any time very, very quickly."
Public hearings to fight online falsehoods: Read the submissions here.