Famous footage of a possible cow abduction from 1983. (Not an incident Mr Mooner claims to have filmed or been present at.)

A man claims to have witnessed a UFO "the size of a transit van" trying to abduct cows in Devon. He believes the aliens were motivated by a desire to harvest the animals' genetic material.

John Mooner said: "I was watching a train pass by in the distance, when I spotted a black object slowly moving along the tree line and at first I thought it was an helicopter. I could only hear the passing train and thought to myself that's strange it can't be an helicopter there's no sound of the rotors.

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"I estimated that the object must of been the size of a large transit van. I watched as the object began to slowly descend into a field. Once it had landed the black object just sat there as if waiting for something to arrive. To my amazement the black object then went completely invisible.

"I wanted to go over there to investigate but it was to far away and I did not have a boat to get across the water. My guess is that the object was waiting for the farmer to bring his livestock into the field so they could abducted some of the poor animals to kill for genetic material.

"The farmer would not of seen this large object and would of [sic] left the field thinking his animals were safe. But the aliens were there all along waiting for the opportunity to strike and take their pickings. Spooky."

Mooner, a self-described "ufologist", has purportedly seen scores of extra-terrestrial spaceships over the years. He made the most recent claims to an Exeter newspaper.