A former US Marine who sensationally claimed that his unit stumbled across a secret military rendezvous with an alien spacecraft says he has been threatened.

He even fears that one day he could be killed by sinister forces that are trying to cover up the Pentagon’s UFO secrets.

Michael Herrera was part of a US Navy humanitarian mission during the 2009 Sumatra earthquake.

READ MORE: Ex-US Marine tells of ‘special forces soldiers loading guns and ammo into a UFO’

After he was “ambushed” by a paramilitary unit he was searched and had his camera confiscated by the mysterious “soldiers in black”.

He was warned several times not to tell anyone about the strange “flying saucer” type craft he had seen in the Sumatran jungle.

After remaining silent about his strange encounter for many years, he told his story last month at a briefing given by Dr Steven Greer’s Disclosure Project.

He has now told podcaster Shawn Ryan that the intimidation from shadowy forces within the US military has increased.

“I’ve had numerous encounters with f***ing helicopters hovering over my house… they were hovering over my dad’s house too,” Michael said.

“They get so low, where they rattle the walls [and] scare the sh*t out of the animals that we’ve got.

“[My dad’s] dogs were going f***ing crazy at that point and he was concerned because he was home and he was like I’ve never heard anything like that.”

Michael said he’s shot video footage of the unmarked black helicopters, and he knows that other UFO whistleblowers – even people within the US government – have been subjected to the same kind of intimidation tactics.

He continued: “There’s just a kind of hysterical factor to this how much money they’re f***ing spending on this to happen to try to either intimidate me or anybody else for that matter.

“There’s some elected officials, and even some government officials I know they’re having the same thing happen to them because they’ve told me about it personally.”

Michael lives close to Denver airport, so he’s optimistic that government contacts can help him trace the source of these mystery flights because they would be travelling through the airport’s restricted airspace.

Michael is concerned that, as he continues to talk about his UFO experience, the intimidation will escalate.

He added: “I don’t feel like harming myself …everybody makes the joke [Jeffrey] Epstein didn’t kill himself …

“So the same goes here. I don’t have any reason to harm myself so if anything happens – it’s not from me”.

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