Ghost caught on film? Bizarre shape zipped past security camera
The footage has been handed to the Mutual UFO Network (MUFON) for further investigation.
It shows a security camera on the outside of an address in Longmont, Colorado, recording from a fixed position on Friday.
The homeowner, who has not been named, but who reported the sighting to experts, wrote to the US-based organisation: "Found this on one of my surveillance cameras.
"I have no idea….winter, no birds, insects or bats.
