High-ranking US government officials have first-hand knowledge" of a secret Pentagon crash retrieval program for UFOs, Sen. Marco Rubio has claimed. Rubio (R-Fla.), who serves as vice chairman of the Senate Intelligence Committee, told NewsNation Monday that "serious" whistleblowers " who "have held very high clearances and high positions within our government" " have come forward to the panel about several incidents in recent years. "Some of these people still work in the government," the 52-year-old Rubio told the outlet. "And frankly, a lot of them are very fearful, fearful of their jobs, fearful [of] their clearances, fearful of their career, and some, frankly, are fearful of harm coming to them." Rubio's comments bolster the testimony of an Air Force veteran and former intelligence official who recently told Congress he had "proof" that the US government had been covertly storing extraterrestrial aircraft for decades. "These are retrieving non-human origin technical vehicles, call it spacecraft if you will, non-human exotic origin vehicles that have either landed or crashed," 36-year-old David Grusch [said]. "Well, naturally, when you recover something that's either landed or crashed, sometimes you encounter dead pilots and, believe it or not, as fantastical as that sounds, it's true." Grusch said the US government even received a tip from the Vatican about a UFO " and later recovered the alien craft from Italian Fascist dictator Benito Mussolini.