In the clip, a mysterious object can be seen floating in the sky.
It appears to be slowly falling towards the ground as the camera zooms in.
Another angle reveals the figure of the shape, appearing to represent a spacesuit.
Discovered in Phoenix, USA, space boffins believe the video shows a “flying humanoid alien landing from space”.
Uploaded to YouTube channel UFOmania yesterday, the footage has received over 30,000 views.
The clip was captioned “UFO and alien hunters have made one of the most bizarre UFO claims ever after viewing a UFO sighting video that emerged online recently.
“According to conspiracy theorists, a short clip submitted recently to the Mutual UFO Network (MUFON) shows a ‘flying humanoid alien’ dressed in a spacesuit over Phoenix in Arizona.
“The alien appeared to be landing from space.”
But some are not so convinced.
One comment read: “Could be a man-shaped balloon weighed down at the feet. This explains the low rate of descent.
“I want to believe as much as anyone, but next time chase it down and get a close-up.”
Another added: “Could also easily be a jetpack.
“Holding its hands downwards suggests it could be a flyboard air kind of thing.”
Just yesterday, alien invasion fears rose after a huge unexplainable light appeared in the night sky.