The big investigative reporting guns are now trained on Donald Trump, as he continues to commandeer the Republican presidential primary season.

In a bombshell new report, Yahoo reporter Michael Isikoff, who was a key figure in exposing the Monica Lewinsky-Bill Clinton scandal, writes that the daughter of a reputed New Jersey mobster says her dad had a long, cozy relationship with Trump. She told Isikoff her father, Robert LiButti, gambled heavily in Trump's casino, rode on his helicopter and hung out on his yacht.

Trump has denied in the past and now again that he had any personal relationship, or even recognized the name, with LiButti, who was banned from Atlantic City casinos over his ties to New York mob boss John Gotti.

But LiButti was a well known figure to gaming investigators, who in 1991 investigated and then fined Trump Plaza $200,000 for accommodating LiButti's desire not to have African Americans or women at his gambling tables.

Nine employees alleged that the casino "repeatedly removed African-Americans and women from craps tables after LiButti, one of the highest-rolling gamblers in the city's history, loudly complained about their presence when he was playing," Isikoff wrote in the report.

LiButti was found to have used racist and vulgar language at the craps table, and investigators concluded that Trump Plaza accommodated the high roller by removing blacks and women from his tables.

Isikoff notes that in 1991, Trump denied knowing LiButti, telling the Inquirer that: "I have heard he is a high roller, but if he was standing here in front of me, I wouldn't know what he looked like."

But LiButti's daughter, Edith Creamer, disputed that in two interviews with Isikoff. She took issue with Trump's breezy brush off of any personal ties to the alleged racist-sexist-reputed-mobster-craps-playing-horse breeder.

"He's a liar," Creamer told Isikoff. "Of course he knew him. I flew in the [Trump] helicopter with [Trump's then wife] Ivana and the kids. My dad flew it up and down [to Atlantic City]. My 35th birthday party was at the Plaza and Donald was there. After the party, we went on his boat, his big yacht. I like Trump, but it pisses me off that he denies knowing my father. That hurts me."

Trump was again asked to comment on his relationship with LiButti for the Yahoo story and again said it didn't really ring a bell.

Through his spokeswoman, Trump sent an email to Yahoo News: "During the years I very successfully ran the casino business, I knew many high rollers. I assume Mr. LiButti was one of them, but I don't recognize the name."