The image, said to have been taken over the mountain in Waikane, Hawaii, is being probed by paranormal investigators from the Mutual UFO Network (MUFON).
It was taken by an unnamed photographer on October 23 before he submitted it the the US-based organisation, which is the biggest in the world devoted to the investigation of aliens and UFOs.
In a report to MUFON, the eyewitness said: “I was taking pictures at Kaneoha Bay at lunch time of the mountains.
“I had on the “multiple pictures” setting which means if I hold down the button of my camera then it will continuously snap photos with not even a second in between shots.
“I had this option on and took multiple picture of the mountains.
“I went to go look back at my pictures when I noticed one of them was not like the others.
“At first I thought a wood chip was on my lens, but I looked closer and I realised I had spotted a UFO.”
The man said he had previously been a sceptic.
He added: “I don’t really believe in stereotypical UFOs but this creeped me out so much that I’m reporting it just in case it really is one.
“The unidentified object I saw was a disk, football shape and it was yellow/orange.
“When I zoom up on my camera, there seems to be a dome on the top as well.
“As soon as I saw the picture and realised it wasn’t a football or wood chip I got a very eerie feeling.
“I showed my brother and dad the photo right when I saw but they didn’t seem to be worried much about it.
“I attached the photos in this report as well.
“The first one should be a plain picture of the mountains and the second one has the weird object in it.
“It seems to be hovering over the mountain in the middle right side of the photo.”
It has also been picked up on by Scott C Waring, editor of ufosightingsdaily.com, who made the shock claims about it being evidence for an alien base.
He wrote: “UFOs are often seen around mountain tops because their exits from the underground bases need to be in locations where few people ever venture.
“That cuts down on the likelihood of them being seen.”
But Mr Waring, who has faced criticism even from other UFO investigators for leaping to conclusions about alleged UFO pictures, admitted manipulating the image to make it clearer.
He added: “I added contrast above to make the UFO come into focus.”
MUFON is investigating the case.