LOS ANGELES, United States (AFP) — A mysterious metal monolith found in the remote desert of the western United States, sparking a national guessing game over how it got there, has apparently disappeared, officials said.

The Bureau of Land Management in Utah said Saturday it had received “credible reports” that the object had been removed “by an unknown party” on Friday evening.

The bureau “did not remove the structure which is considered private property”, it said in a statement.

“We do not investigate crimes involving private property which are handled by the local sheriff’s office.”

The shiny, triangular pillar, which protruded 12 feet from the red rocks of southern Utah, was spotted on November 18 by baffled local officials counting bighorn sheep from the air.

After landing their helicopter to investigate, Utah Department of Public Safety crew members found “a metal monolith installed in the ground” but “no obvious indication of who might have put the monolith there”.

News of the discovery quickly went viral, with many noting the object’s similarity with strange alien monoliths that trigger huge leaps in human progress in Stanley Kubrick’s classic sci-fi film 2001: A Space Odyssey.

Others remarked on its discovery during a turbulent year that has seen the world gripped by the novel coronavirus pandemic, and optimistically speculated it could have a different function entirely.

“This is the ‘reset’ button for 2020. Can someone please press it quickly?” joked one Instagram user.

“There are roads close by, but to haul the materials to cut into the rock, and haul the metal, which is taller than 12 feet in sections — to do all that in that remote spot is definitely interesting,” Nick Street, a spokesman for the Department of Public Safety told the New York Times.