The mysterious "Dudley Dorito" UFO has been spotted for the fourth time in five years flying through a cloudless sky over woodland in Yorkshire.
The object, which looks like an extra-terrestrial tortilla chip, was captured by an amateur cameraman who posted the footage on YouTube.
He can be heard saying "I don't know what that is" as the triangular aircraft glides silently across the frame above a forest in the north of England.
The UFO was dubbed the Dudley Dorito after its first sighting over the Midlands in 2007 but it is unclear whether the YouTube footage is real or a hoax.
Eye-witnesses first saw the black triangle hovering over Halesowen and they reported the close encounter to UFORM, a local group of UFO-spotters.
Then in 2010 David Allan from Sutton Coldfield reported seeing a triangular object four or five times bigger than an aeroplane in the skies on Bonfire Night.
A few weeks after that 21-year-old quality inspector Minuesh Mistry saw the Dudley Dorito hovering above his home in Tipton in the West Midlands.
But the phenomenon of "black triangle" UFOs has been dismissed as similar to the effect ball lightening has on the atmosphere.
Project Condign was the name of a study undertaken by Defence Intelligence Staff between 1997 and 2000.
The MOD department claimed the airborne objects were "supernormal atmospheric plasma phenomenon".
The X-files were made publically available in 2005 after an FOI request.