Donald Trump's campaign CEO, Stephen Bannon , is under investigation to determine if he was illegally registered to vote in Florida after a report last week revealed he did not live at a house in the state where he had been registered.

Election officials in Miami-Dade County confirmed to NBC News that prosecutors had requested voter records for Bannon, the chairman of Breitbart News who formally joined the GOP nominee's campaign earlier this month.

"I know that there is an investigation but I know very little about it," Rosy Pastrana, executive assistant to the county's election supervisor, told NBC News . "They requested voter records for him, which is why I know there is an investigation going on."

Pastrana said it wasn't obvious to her whether Bannon had fraudulently registered, since he had not voted in Miami-Dade since registering there in April 2014.

"There is nothing here that I see that he did wrong," she said.

But under Florida law, it is a felony punishable by up to five years in prison to knowingly submit false information when registering to vote. Florida requires a person to be a legal resident of the state and of the county where they are registered, and applicants are asked to provide a Florida driver's license, state identification number or the last four digits of their Social Security number.

Pastrana said Bannon submitted his Social Security information, according to NBC News, and the Florida Department of Highway Safety and Motor Vehicles said Bannon has neither a driver's license nor a state ID.

Bannon's registration status came under suspicion last week after The Guardian reported that the house at his registration address had been vacant for months, and that while Bannon's ex-wife had lived there, Bannon did not.

Bannon reportedly owns property in Laguna Beach, California, and until 2014, he had been registered to vote in Orange County. He also co-owns property in Los Angeles and often stays in Washington at the so-called Breitbart Embassy, a townhouse steps away from the Capitol that is owned by Egyptian businessman Mostafa El-Gindy.

Roughly a week before The Guardian story published, according to NBC News, Bannon submitted a form to change his registration to a Sarasota County, Florida, address listed as a home in Nokomis owned by Breitbart News writer Andy Badolato.

Kurt Bardella, a former Breitbart spokesman, told NBC that Bannon "spent a lot of time in Florida."