Speaking at a CNN Republican debate, Mr Rubio claimed Mr Trump hired illegal workers from Poland and was later fined $1 million.
“You're the only person on this stage that's ever been fined for hiring people to work on your projects illegally,” Mr Rubio said to Mr Trump.
“You hired some ... He hired workers from Poland ... People can look it up. I'm sure people are Googling it right now. Trump Polish workers. You’ll see $1 million for hiring illegal workers on one of his projects. Yeah he did it”.
The Republican presidential frontrunner dismissed the old lawsuit as something which happened decades ago.
“He brings up something from 30 years ago. It worked out very well. Everybody was happy. By the way the laws were totally different that was a whole different world,” replied Mr Trump.
Later in the discussion, Mr Rubio added: ”If he builds the wall the way he built Trump Towers, he'll be using illegal immigrant labour to do it ... It's not a sound bite. It's a fact. Again, go online and Google it. Donald Trump, Polish workers.“
Donald Trump's most controversial quotes
Donald Trump's most controversial quotes
1/14 On Isis:
"Some of the candidates, they went in and didn’t know the air conditioner didn’t work and sweated like dogs, and they didn’t know the room was too big because they didn’t have anybody there. How are they going to beat ISIS?"
2/14 On immigration:
"I will build a great wall — and nobody builds walls better than me, believe me —and I’ll build them very inexpensively. I will build a great, great wall on our southern border, and I will make Mexico pay for that wall. Mark my words."
3/14 On Free Trade:
"Free trade is terrible. Free trade can be wonderful if you have smart people. But we have stupid people."
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4/14 On Mexicans:
"When Mexico sends its people, they’re not sending their best. They’re sending people that have lots of problems. They’re bringing drugs. They’re bringing crime. They’re rapists."
5/14 On China:
"I just sold an apartment for $15 million to somebody from China. Am I supposed to dislike them?... I love China. The biggest bank in the world is from China. You know where their United States headquarters is located? In this building, in Trump Tower."
6/14 On work:
"If you're interested in 'balancing' work and pleasure, stop trying to balance them. Instead make your work more pleasurable."
7/14 On success:
"What separates the winners from the losers is how a person reacts to each new twist of fate."
8/14 On life:
"Everything in life is luck."
9/14 On ambition:
"You have to think anyway, so why not think big?"
10/14 On his opponents:
"Bush is totally in favour of Common Core. I don't see how he can possibly get the nomination. He's weak on immigration. He's in favour of Common Core. How the hell can you vote for this guy? You just can't do it."
11/14 On Obamacare:
"You have to be hit by a tractor, literally, a tractor, to use it, because the deductibles are so high. It's virtually useless. And remember the $5 billion web site?... I have so many web sites, I have them all over the place. I hire people, they do a web site. It costs me $3."
12/14 On Barack Obama:
"Obama is going to be out playing golf. He might be on one of my courses. I would invite him. I have the best courses in the world. I have one right next to the White House."
13/14 On himself:
"Love him or hate him, Trump is a man who is certain about what he wants and sets out to get it, no holds barred. Women find his power almost as much of a turn-on as his money."
14/14 On America:
"The American Dream is dead. But if I get elected president I will bring it back bigger and better and stronger than ever before and we will make America great again."
Mr Rubio’s comments refer to reports of undocumented workers working at Trump properties.
In the 1980s the real estate mogul faced a lawsuit alleging that undocumented Polish demolition workers worked on Trump Tower in Manhattan.
It wasn’t until 1999 that the suit was settled but the settlement has never been made public.
More recently, in 2015, The Washington Post suggested undocumented workers may have been involved in building a $200 million luxury Trump hotel which sits six blocks from the White House in downtown Washington.Reuse content