US President Donald Trump says he has fired a top election official who contradicted his claims of voter fraud.
Trump said he "terminated" Cybersecurity and Infrastructure Security Agency (Cisa) chief Chris Krebs for his "highly inaccurate" remarks on vote integrity, reports BBC.
Mr Trump has refused to concede the US election, making unsubstantiated claims of "massive" voter fraud.
Election officials said the vote was the "most secure" in US history.
Last week the president fired Department of Defense Secretary Mark Esper, amid reports that he doubted the Pentagon chief's loyalty.
There is speculation in Washington DC that before Mr Trump leaves office in January, CIA director Gina Haspel and FBI director Christopher Wray could also be for the chopping block.
Like many others fired by Mr Trump, Mr Krebs only learned he was out of a job when he saw the president's tweet on Tuesday, a person close to him told Reuters news agency.
But following his dismissal, the former Microsoft executive appeared to have no regrets.
He had run the agency from its inception two years ago in the aftermath of alleged Russian meddling in the 2016 election.
To guard against potential cyber-threats, Cisa works with state and local election officials and the private companies that supply voting systems, while monitoring ballot tabulation and the power grid.
Why was Krebs fired?
He had reportedly incurred the White House's displeasure over a Cisa website called Rumor Control, which debunked election misinformation, much of it amplified by the president himself.
Reuters reports that the White House was particularly unhappy with a Krebs post that had debunked a conspiracy theory about an intelligence agency supercomputer named Hammer and Scorecard supposedly tampering with the national vote count.
Mr Krebs and other former US officials have said that no such system exists.
Shortly before he was fired, he posted a tweet that appeared to take aim at Mr Trump's allegation that voting machines in various states had switched ballots to his rival Joe Biden.
Mr Krebs tweeted: "ICYMI: On allegations that election systems were manipulated, 59 election security experts all agree, 'in every case of which we are aware, these claims either have been unsubstantiated or are technically incoherent.' #Protect2020".
He was among senior officials from the Department of Homeland Security who last week declared the 3 November US general election the "most secure in American history", while rejecting "unfounded claims".
Though that statement did not name Mr Trump, on the same day it was published Mr Krebs retweeted a Twitter post by an election law expert saying: "Please don't retweet wild and baseless claims about voting machines, even if they're made by the president."