The U.S. Navy’s acknowledgment that the 2004 videos of an encounter with a UFO were real has caused much consternation. Now, a new report says two “unknown individuals” told several Naval officers who witnessed the event, known as the USS Nimitz UFO incident, to delete evidence.

The report, published in Popular Mechanics, cites interviews with five Navy veterans who discussed what they experienced at the time while they were sailing on the USS Princeton on Nov. 14, 2004, off the coast of southern California.

One of the men, Gary Voorhis, said he was chatting with some of the radar techs on the USS Princeton when he heard them talking about “ghost tracks” and “clutter” on the radar system, a state-of-the-art Cooperative Engagement Capability (CEC) and AEGIS Combat System.

The air control systems were taken down, recalibrated to clear out the supposed false alarms when the tracks got clearer, he said.

“Once we finished all the recalibration and brought it back up, the tracks were actually sharper and clearer,” Voorhis told the news outlet. “Sometimes they’d be at an altitude of 80,000 or 60,000 feet. Other times they’d be around 30,000 feet, going like 100 knots. Their radar cross sections didn’t match any known aircraft; they were 100 percent red. No squawk, no IFF (Identification Friend or Foe).”

Operations Specialist Senior Chief Kevin Day said in the documentary film, The Nimitz Encounters, that his job was to “man the radars and ID everything that flew in the skies.”

On or around Nov. 10, approximately 100 miles off the San Diego coast, Day noticed the stranger tracks on the radar.

“The reason why I say they’re weird [is] because they were appearing in groups of five to 10 at a time and they were pretty closely spaced to each other. And there were 28,000 feet going a hundred knots tracking south,” Day said in the documentary.

The Navy eventually sent out fighter jets to get a look at the object, with one succeeding in getting it on video–the now-famous black-and-white tape that was released publicly in 2017. Along with that tape, there were two other video recordings from years later that were released publicly by the New York Times, Fox News has previously reported.

The videos in question, known as “FLIR1,” “Gimbal” and “GoFast,” were originally released to the New York Times and to The Stars Academy of Arts & Science, co-founded by former Blink 182 rocker Tom DeLonge.

The first video of the unidentified object was taken on Nov. 14, 2004, and shot by the F-18’s gun camera. The second video was taken on Jan. 21, 2015, and shows another aerial vehicle with pilots commenting on how strange it is. The third video was also taken on Jan. 21, 2015, but it is unclear whether the third video was of the same object or a different one.

After the incident with the “Tic Tac”-shaped object that Voorhis said gave off “a kind of a phosphorus glow” at night while darting around, two “unknown individuals” took all of the data recordings.

“They were not on the ship earlier, and I didn’t see them come on. I’m not sure how they got there,” said P.J. Hughes, who was miles away from the Princeton, and was unaware of the unidentified objects, in the interview.

Hughes added that he was told by his commanding officer to turn over the recently secured hard drives of the airborne early-warning aircraft, the E-2 Hawkeye.

“We put them in the bags, he took them, then he and the two anonymous officers left,” Hughes said.

On the Princeton, Voorhis described a similar situation.

“These two guys show up on a helicopter, which wasn’t uncommon, but shortly after they arrived, maybe 20 minutes, I was told by my chain of command to turn over all the data recordings for the AEGIS system,” Voorhis added in the interview with Popular Mechanics.

It may be convenient to blame “unknown individuals” for the disappearance of the tapes, but Cmdr. David Fravor, one of the pilots who was able to get a close view of the object, said people accidentally erased and recorded over them.

“You know how it is when you go to and from cruise,” Fravor said in a January interview on The Fighter Pilot Podcast. “Someone goes, ‘What are these? Hey, they look like blank 8mm tapes. We’ll just use them.”

Earlier this year, the Navy issued new classified guidelines on how to report such instances “in response to unknown, advanced aircraft flying into or near Navy strike groups or other sensitive military facilities and formations.”

The Defense Department also briefed Senate Intelligence Committee Vice Chairman Mark Warner, D-Va., in June, along with two other senators, as part of what appeared to be heightened efforts to inform politicians about naval encounters with unidentified aircraft.

Warner’s spokesperson indicated that the senator sought to probe safety concerns surrounding “unexplained interference” naval pilots faced, according to Politico. The outlet reported more briefings were being requested as news surfaced that the Navy revised its procedures for personnel reporting on unusual aircraft sightings.

President Trump said he has been briefed on Navy pilots’ reported sightings of unidentified flying objects, but remained skeptical of the existence of UFOs.

“I want them to think whatever they think,” Trump told ABC News’ George Stephanopolous earlier this year, referring to the Navy pilots. “I did have one very brief meeting on it. But people are saying they’re seeing UFOs. Do I believe it? Not particularly.”

In December 2017, Fox News reported that the Pentagon had secretly set up a program to investigate UFOs at the request of former Sen. Harry Reid, D-Nev., who expressed his desire earlier this year for lawmakers to hold public hearings into what the military knows.

Fox News’ Bradford Betz, Louis Casiano and Sam Dorman contributed to this report.