The head of a U.S. government agency tasked with helping secure the 2020 elections was fired on Tuesday, after using his position to publicly debunk a series of election fraud conspiracy theories embraced by President Donald Trump and other Republicans.

“The recent statement by Chris Krebs on the security of the 2020 Election was highly inaccurate, in that there were massive improprieties and fraud,” President Trump tweeted, announcing that Krebs had been terminated.

Krebs ran the “Rumor Control” website of the Cybsersecurity and Infrastructure Security Agency, which aimed to combat 2020 voting conspiracy theories - a number of which had been touted by the President.

In his own tweet, Krebs defended his work.

“Honored to serve. We did it right,” Krebs wrote.

“It speaks volumes that the president chose to fire him simply for telling the truth," said Sen. Mark Warner (D-VA) of Krebs.

“In typical style, he purges a truthteller and riddles the announcement with corrosive, undemocratic, dangerous lies,” said Rep. Lloyd Doggett (D-TX).

“He protected our democracy. And spoke truth to power,” said Rep. Adam Schiff (D-CA). “That’s why Trump retaliated and fired him.”

Amid reports that he expected to be fired, Krebs in recent days repeatedly knocked down a series of post-election claims made by GOP officials and lawmakers, and allegations which spread quickly on social media.

Among the subjects publicly noted by Krebs:

+ A claim of ballot problems noted by President Trump in California was not true.

+ Knocked down social media claims that different vote totals for candidates from the same party were proof of fraud.

+ Rejected allegations of rampant voting by dead people.

+ Undercut charges that major vote total changes were secretly made after Election Day.

+ Defended Arizona elections officials from allegations of voting irregularities.

+ Red-flagged fake charges of election fraud in Wisconsin.

+ Disputed accusations involving a vote tabulation error in Michigan.

+ Knocked down a conservative conspiracy theory known as “Hammer and Scorecard.”

The Hammer and Scorecard matter has consumed many on social media in recent days, with Republicans claiming it is evidence that voting software was used to change vote totals around the nation - something echoed by President Trump on Twitter.

But Krebs bluntly said it wasn’t true.

“And don’t forget, Hammer and Scorecard is still nonsense,” Krebs tweeted on last week.

The “Rumor Control” work about the elections attracted a lot of media attention in recent days as well.