Donald Trump on billionaire he's been trashing all week: Who?

Real-estate magnate Donald Trump denied a Wednesday report in Politico that detailed his outreach to the same billionaire megadonors he's been zinging on the campaign trial.

In fact, Trump even suggested he didn't know one of those donors, hedge-fund bigwig Paul Singer.

"I don't know who Paul Singer is," Trump said Thursday on MSNBC's "Morning Joe."

This is despite the fact that Trump repeatedly criticized Singer's support for immigration reform this week. Singer, a highly influential donor, recently revealed his support for Sen. Marco Rubio's (R-Florida) presidential campaign.

"Paul Singer represents amnesty and he represents illegal immigration pouring into the country, and now he's with Rubio," Trump told his supporters Wednesday in New Hampshire, according to Bloomberg Politics.

"This new gentleman that's backing [Rubio], Singer, you got to look at that record, OK? You take a look at look at that record. You take a look at what he stands for," Trump said during a "Good Morning America" interview on Tuesday.

"Further proof that Gang of Eight member Marco Rubio is weak on illegal immigration is Paul Singer's, Mr. Amnesty, endorsement.Rubs can't win," Trump tweeted on Sunday.

In addition to Singer, Politico's Ben Schreckinger and Ken Vogel reported that Trump's presidential campaign was once trying to woo casino mogul Sheldon Adelson and energy magnates Charles and David Koch. The reported outreach raised eyebrows because Trump has accused his opponents of trying to be those billionaires' "puppets."

During his "Morning Joe" interview, Trump admitted he had talked to Adelson. But he said that was no big deal because he and Adelson agree on the casino magnate's signature issue: Israel. Trump, who is also a billionaire, stressed that he is self-funding his campaign and doesn't want any free-spending super PACs to support him.

"I had one conversation with Sheldon and all he wants to do is protect Israel. But I don't want his money. I don't need his money. I am putting up my own money," Trump said. "I will protect Israel. "

Trump also trashed Politico in general.

"Politico is so dishonest in so many different things," he said on MSNBC. "This Politico website, or whatever the hell they call it, I mean, they write about me. We don't even deal with them anymore, because their level of dishonesty is so incredible."