UFO whistleblowers are facing alleged attempts to silence them as they move to expose what they believe are some of America's most closely guarded secrets.

Investigative journalist Jeremy Corbell, who has helped bring multiple whistleblowers before Congress, warned that the risks facing these individuals extend far beyond public scrutiny.

'They're giving up their security clearance, they're giving up their security, they're putting their family at risk, they're putting themselves at risk, if by stigma alone,' Corbell, who details several cases in his upcoming film Sleeping Dog, told the Daily Mail.

One of the central cases featured in the film involves Air Force veteran Dylan Borland, who testified before Congress in 2025 about encountering a 100-foot triangular craft near Langley Air Force Base in Virginia while stationed there.

'Since then, my family, former coworkers, friends, and I have endured a level of harassment I have never experienced,' Borland told the Daily Mail.

'I do not know what the future holds because factions within the US Government appear to be openly and knowingly working to cover this up.'

He alleged that false documents were created and intelligence products generated under his name following his testimony.

Corbell also pointed to the death of former US Air Force intelligence officer Matthew Sullivan, 39, who died in 2024 before he could testify in a whistleblower hearing involving UFO-related programs.

'His death is so suspicious in more ways than people know that the FBI and Congress are involved,' Corbell said.

Sullivan had worked in roles connected to military intelligence and advanced technology programs and was reportedly scheduled to provide testimony about classified UFO-related matters before his sudden death.

Corbell said the timing raised serious concerns, saying: 'This is very uncharacteristic in so many ways of what's going on, and the timing of it is so bad.

'Maybe he was so distraught that he took his own life. I wasn't there, I don't know. But I do know that the FBI and Congress and people who knew him very well see this as extremely suspicious, and it is being investigated.'

While officials have not released full details surrounding the circumstances of Sullivan's death, the involvement of federal investigators has heightened fears among some whistleblowers about the risks tied to coming forward.