It all sounds a little too inspired by the X-Files, but you never know.....
A little background to this link. It was forwarded to me by one of my best friends. He is ex-US Special Forces. It's safe to say he's "been there" and "done that". As far as I'm aware, he didn't get a T-shirt.
We were once discussing the cinema classic (well, that's what I think of it), Predator. I ventured, "There's no reason something like this couldn't really happen."
My friend, who has spent an awful lot of time in the kinds of jungles depicted in Predator, replied, "Or hasn't already."