Story highlights Murphy says his family has "never done business with Donald Trump" in an interview with CNN.

CNN's KFile unearthed a photo showing Murphy's father and Trump at a 2007 groundbreaking ceremony.

(CNN) Patrick Murphy, the Democrat in Florida trying to unseat Sen. Marco Rubio in November, is standing by his claim that his family has never done business with Donald Trump.

Rubio has tried to deflect attacks on his own relationship with Trump by pointing to Murphy's family business, Coastal Construction, which constructed two Trump-branded buildings in Florida. Murphy has denied any business connection with Trump, claiming that the company dealt solely with the developer, who separately made the decision to license Trump's name on the buildings.

In an interview with CNN's Brooke Baldwin on Friday, Murphy was asked about a photograph, unearthed by CNN's KFile, showing his father and Trump at a 2007 groundbreaking ceremony for Trump Hollywood.

"Politifact has looked into this, we have never done business with Donald Trump and Politifact verified that because we haven't," Murphy said. (PolitiFact rated Murphy's denial "half true," noting that Coastal Construction did not have a direct partnership with Trump but that the company and Trump were involved in the same project together.)

"See, Sen. Rubio unfortunately doesn't understand the way business works," Murphy continued. "He's never been in the private sector. He's been a career politician and a lobbyist. Our family business, we are general contractors. We work for developers. What that developer does, who they hire, whether it's an architect, whether it's a licensing agreement, is their prerogative. But we have never done business with Donald Trump, and it's kind of funny to me, actually, that Sen. Rubio is trying to tar me with Donald Trump, because he knows how dangerous and how much that is hurting him, which is why Sen. Rubio has been dodging him on the campaign trail, you've seen him avoid him at these campaign stops."

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