The metal monolith was discovered by a helicopter crew. Photo: Shutterstock.

Mystery surrounds a huge metal monolith found in a US desert by scientists counting sheep. The experts saw the strange object - reminiscent of the monolith made famous in Stanley Kubrick movie 2001 - while flying over Utah on Wednesday and decided to investigate. The structure is believed to be man-made, approximately 12ft tall,  planted deep in the ground and made of shiny metal, setting it off from the red rock around it.

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Pilot Bret Hutchings, who was flying the helicopter when they spotted it, spoke to local news channel KSLTV, saying: “That’s been about the strangest thing that I’ve come across out there in all my years of flying. One of the biologists is the one who spotted it and we just happened to fly directly over the top of it," he continued.

"He was like, 'Whoa, whoa, whoa, turn around, turn around!' And I was like, 'what,'" said Hutchings. "And he’s like, 'There's this thing back there - we've got to go look at it!'"

No one knows how or why it ended up out in the Utah desert. Photo: Shutterstock.

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The film's monolith - large and a different colour to this one - was made famous in an opening scene where apes discover it. Other theories are that is a piece of artwork, and it has been noted how similar it is to the previous work of John McCracken, who’s minimalist sculptures resemble the monolith. However, Mr McCracken died in 2011. A spokesperson for his gallerist, David Zwirner, first told the Guardian that the monolith was not one of his works, but possibly a fellow artist paying homage. However, they later told the New York Times that it could actually be a McCracken.

“The gallery is divided on this,” Zwirner said. “I believe this is definitely by John.”