"That's why he wants amnesty," Trump told Erin Burnett during an interview on "Erin Burnett OutFront."
The billionaire repeatedly pointed to Rubio's efforts in support of a 2013 bipartisan immigration reform bill, which passed the Senate but stalled in the House, as evidence against his Republican primary rival.
"He was always in favor of amnesty, he was always in favor of letting people pour into the country," Trump said, "then what happened is, when people found that out, he sank like a rock in the water."
Trump also suggested that no more than 10% of the 11 million undocumented immigrants living in the country pay taxes.
"Illegal immigration, each year, costs us between $200 billion and $300 billion," the real estate mogul told Burnett. "I don't know if anybody gives you those numbers. Probably not."
Trump insisted that people living in the U.S. without documentation are avoiding taxation at all levels.
"Do you really believe they pay taxes?" Trump asked Burnett in a clip of the interview that first aired on "The Lead with Jake Tapper."
Burnett pushed back on Trump's claim, noting that undocumented immigrants' incomes are often taxed by state and local governments.
"But there's very little, percentage-wise," Trump said. "There's very little, probably 5 percent, 10 percent."
Between 50% and 75%
of undocumented immigrants pay some taxes, according to information in a 2007 report from the Congressional Budget Office.
"The IRS estimates that about 6 million unauthorized immigrants file individual income tax returns each year," the CBO said, while also citing statewide reports, including one out of California, that showed "75% had taxes withheld from their paychecks, filed tax returns, or both."