Florida Congressional Republicans, led by U.S. Sen. Marco Rubio, pressed Friday for answers on flights that brought undocumented immigrants from the border to interior cities, including Jacksonville.

The flights have been a cause of concern for Republicans in recent weeks, including Gov. Ron DeSantis and Jacksonville Mayor Lenny Curry.

Rubio was joined by U.S. Sen. Rick Scott and 13 members of Congress on the letter to U.S. Department of Homeland Security (DHS) Secretary Alejandro Mayorkas and U.S. Attorney General Merrick Garland. The lawmakers say the "transfer of illegal immigrants into our communities has been done under the cover of night and with a veil of secrecy."

The signatories want to know "who is being transported, their immigration status, whether they have been tested for COVID-19 or have shown proof of vaccination, final destinations and any applicable security reviews performed."

"Information should also include when the transportation first took place, the number of migrants transported to date, as well as future planned or estimated travel, whether state, county or local government entities were alerted prior to arrival and any federal resources provided to assist with the migrants, and any follow-up actions, including whether a notice to appear was issued," the letter urged.

Rubio has expressed concern about this matter independently in recent days, including spotlighting the apparent pattern of flights on a national television appearance. He has been careful to distance himself from claims of having independently verified the flights, however, sourcing the reporting to Jacksonville local station WJXT.

Thursday on the Fox Business Network, the Senator said "that wasn't me who was saying it, that was a local media outlet down there that found it and just looked at the last six months. There's more flights than that. They're probably still ongoing. And they haven't notified anyone, talked to anyone about it."

The Senator's assertions that the local media outlet "found" the information aren't completely accurate, either. Though News4Jax did report the story, they noted the information was provided by the Florida Department of Law Enforcement. Furthermore, they found inconsistencies in the documentation.

"Not all of the records News4Jax received made sense. One flight came from Ireland, for example, and another involves the National Guard. News4Jax has asked the state to clarify," the news outlet published Wednesday.

A spokesperson for Gov. Ron DeSantis attributed the FDLE documents to "a reliable and confidential source who provided information about numerous flights coming into Jacksonville from various locations transporting what was believed to be potential illegal immigrants."

In comments earlier this month, the Governor suggested sources from inside the federal government were divulging this information.

"I know when we initially got wind of this, it wasn't through normal channels. It was people in the federal government who were effectively leaking this to us so that we have a heads up on it," DeSantis said.