Mr Tapper said there was “zero evidence” for President Trump’s “fictional” belief that three to five million votes were illegally cast for Hillary Clinton in November.
White House press secretary Sean Spicer has attributed Trump’s stance to “studies and information he has”, but a clearly enraged Mr Tapper said it simply did not happen.
Speaking on CNN's 'The Lead', Mr Tapper said: “President Trump is claiming and the White House is reaffirming the fiction that millions of illegal votes were cast in the 2016 election.
“It is empirically a stunning allegation for which the White House is providing no evidence and there is a reason they are providing no evidence, there is no evidence. It is not true.
“There’s zero evidence of widespread voter fraud in the 2016 election.”
Jake Tapper dismissed Trump's vote rig claim
There’s zero evidence of widespread voter fraud in the 2016 election
He added if there had been major voter fraud, the President would be “derelict” not to order a major investigation.
Donald Trump first made the vote rigging claim weeks after his election day victory. A late influx of provisional and absentee ballots contributed to Mrs Clinton’s tally.
She finished with around three million more votes than the 70-year-old but Mr Trump won the decisive electoral college vote by a margin of 304-227.
President Trump's Key Moments
Wed, January 25, 2017
Our pick of the top key moments so far for the 45th President of the United States, Donald J. Trump.
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US President Donald Trump delivers remarks after signing five executive orders related to the oil pipeline industry in the oval office of the White House in Washington, DC, USA
This is the latest in an ongoing battle between Mr Trump and the network.
CNN has questioned whether Mr Trump can keep his promise of building a wall along the US-Mexico border to keep illegal immigrants out.
Correspondent Ed Lavandera spent two months travelling the length of the US southern border with Mexico and stated parts of the terrain were not possible to build a wall on.
Sean Spicer said Trump had
Mr Lavandera said: “This is the landscape in the Big Bend area of Texas and that is the challenge. How in the world do you build a wall in this kind of terrain?”
CNN has been criticised after it aired a segment covering what would happen if everyone at Mr Trump's inauguration was killed.
The network also had a recent disagreement with the President, who in a press conference refused to speak to one of its senior reporters, claiming they were "fake news".
The falling out was triggered over the explosive allegations that Russia was in possession of compromising material related to Mr Trump.