A four-foot transparent “alien” has been spotted taking a stroll in an area plagued by “inter-dimensional portals”.

The “grey being” was pictured with long limbs and a peculiar walk near the Pilcomayo River in Tarija, Bolivia.

The extra-terrestrial wasn't shy as it appeared to be staring at an unassuming onlooker in the snap.

Even more bizarrely, there doesn’t appear to be a reflection from the alien in the water it's walking by.

Now, the country's top UFO experts are debating the authenticity of the image that has gone viral online as “the alien from Tarija”.

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