(Reuters) - Russian operatives have penetrated some of Florida’s election systems and could delete registered voters ahead of the November elections if the systems are not adequately protected, Florida U.S. Senator Bill Nelson told the Tampa Bay Times on Wednesday.

FILE PHOTO - Senator Bill Nelson (D-FL) testifies to the Senate Judiciary Committee during a hearing about legislative proposals to improve school safety in the wake of the mass shooting at the high school in Parkland, Florida, on Capitol Hill in Washington, U.S., March 14, 2018. REUTERS/Joshua Roberts

“They have already penetrated certain counties in the state and they now have free rein to move about,” Nelson told the newspaper, which posted an audio recording of the interview on its website.

Democrat Nelson and Republican Senator Marco Rubio of Florida wrote a letter last month to the state’s 67 county election supervisors about potential threats, the newspaper said. But that letter lacked the specificity Nelson has laid out, according to the Times.

“We were requested by the chairman and vice chairman of the (Senate) Intelligence Committee to let supervisors of election in Florida know that the Russians are in their records,” Nelson told the newspaper.

But the state department that oversees elections pushed back against Nelson’s comments, saying it received “zero information” from Nelson, federal or state agencies to support the infiltration claim. Nelson is running for re-election in November against Florida Governor Rick Scott.

“If Senator Nelson has specific information about threats to our elections, he should share it with election officials in Florida,” said Sarah Revell, spokeswoman for the Florida Department of State, adding that state and local officials received funding to strengthen the security of election systems.

Rubio’s office declined comment. The Senate Intelligence Committee did not immediately respond to requests for comment.

“This is no fooling time and that’s why two senators, bipartisan, reached out to the election apparatus of Florida to let them know the Russians are in your records and all they have to do, if those election records are not protected, is to go in and start eliminating registered voters,” Nelson told the Times.

“You can imagine the chaos that would occur on Election Day when the voters get to the polls” and discover they are no longer registered, he said.

U.S. intelligence agencies have concluded that Russian operatives targeted the 2016 presidential race with a hacking and disinformation campaign to try to tilt the election in President Donald Trump’s favor. They said they found no evidence vote tallies were changed.

U.S. intelligence officials have said Russian election interference efforts are continuing and now target the Nov. 6 elections.