Donald Trump blasted his former campaign opponent on Wednesday for denying her role in paying for opposition research that grew into an election-year 'dirty dossier' full of salacious and unsubstantiated allegations against him.

'Don't forget Hillary Clinton totally denied this. She didn't know anything. She knew nothing,' Trump said in an interview with the Fox Business Network's 'Lou Dobbs Tonight' program.

'What I was amazed at – it's almost $6 million that they paid, and it's totally discredited. It's a total phony. I call it fake news. It's disgraceful. It's disgraceful.'

Campaign finance records show that the Clinton campaign paid a Washington law firm called Perkins Coie $5.6 million in legal fees from June 2015 to December 2016, and the Democratic National Committee paid another $3.6 million. The law firm was a pass-through, taking money from the campaign and the DNC and paying the opposition research Fusion GPS.

It's impossible to know how much of that money was earmarked for Fusion GPS's work on the now-discredited dossier.

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President Donald Trump blasted Democrats on Wednesday, including Hillary Clinton, for covering up their role in funding opposition research that led to a 'dirty dossier' of unsubstantiated allegations against him

The Clinton campaign and the Democratic National Committee funneled money to the opposition research firm Fusion GPS through a law firm

On the air Wednesday night with Lou Dobbs, Trump said 'that's the collusion' when pointing to Hillary Clinton's connection to the unsubstantiated dirty dossier

'I think it's very sad what they've done with this fake dossier. It was made up, and I understand they paid a tremendous amount of money,' the president told reporters at the White House before boarding Marine One on his way to Dallas, Texas.

Trump said the Clinton campaign and the DNC would have succeeded in hiding their involvement, but for a court case that threatened to expose them anyway.

'Hillary Clinton always denied it, the Democrats always denied it. And now only because it's going to come out in a court case, they said yes they did it. They admitted it and they're embarrassed by it,' he said.

Last week Fusion GPS asked a federal judge to block a congressional subpoena for its bank records, which would show who paid for the dirt-digging.

Trump called the situation 'a disgrace' and 'a very sad commentary on politics in this country.'

'They are very embarrassed by it,' he said of the Democrats.

Christopher Steele, a former British spy contracted by Fusion GPS to conduct the anti-Trump research, reportedly relied on Russian intelligence agencies for some of his source material.

That, Trump suggested Wednesday, has flipped a months-long media and Democratic narrative about his own alleged collusion with Moscow on its head.

Trump said Democrats couldn't rationalize Clinton's defeat without a scapegoat, so 'they made up the whole Russia hoax. Now it's turning out that the hoax has turned around'

Democrats, he said, couldn't rationalize her defeat without a scapegoat, so 'they made up the whole Russia hoax. Now it's turning out that the hoax has turned around.'

'That’s the real collusion. Believe me,' Trump told Dobbs, adding that even Democrats come out of walk out of meetings on Capitol Hill saying, 'there is no collusion and we haven’t found any yet but we’ll keep going.'

Before Steele's involvement led to the dossier's production, an unnamed Republican primary campaign funded some early opposition research on Trump, also conducted by Fusion GPS.

The president said Wednesday that he has an idea who was behind it, but doesn't want to hazard a guess publicly.

'I think I would know, but let's find out who it is. I'm sure that will come out,' he told reporters on the south lawn of the White House.

'If I were to guess, I have one name in mind.'

He made a similar claim on Dobbs' program Wednesday night.

The Washington Post first revealed the source of funding for the dossier Tuesday night, leading Trump to characterize himself as 'the victim' on Wednesday morning

Hillary Clinton's campaign lawyer Marc E. Elias hired Fusion GPS in April 2016 to dig up dirt about Donald Trump, but falsely denied involvement to reporters

And a pair of New York Times reporters revealed that the Clinton campaign lawyer who brokered the dossier research deal denied involvement in the project for a year as journalists pressed him for information.

Marc Elias was the go-between linking the Clinton camp, the Democratic National Committee and Fusion GPS to dig up dirt on the president while he was running for office.

'Folks involved in funding this lied about it, and with sanctimony, for a year,' Times reporter Maggie Haberman tweeted after The Washington Post linked the dossier to Elias and his law firm Perkins Coie.

Kennth Vogel, another Times journalist, tweeted: 'When I tried to report this story, Clinton campaign lawyer @marceelias pushed back vigorously, saying "You (or your sources) are wrong".'