The mystery of the increasingly intricate patterns was supposedly solved after several high-profile cases were revealed to be the work of artists and mischief-makers armed with barrels, planks of wood and plenty of spare time.
Credit for the hoaxes has been laid largely at the feet of pranksters Dave Chorley and Doug Bower, who in 1991 announced they had been pulling the wool over people's eyes since 1978.
(FYI, crop circles have also been blamed on unusual weather patterns, top secret military experiments and, er, stoned wallabies.)
But research by Greg Jefferys has revealed evidence of the strange circles in the English countryside at least 33 years before Chorley and Bower took credit for the phenomena - which until then had been attributed to UFOs and alien activity.
Jefferys, who has a degree in archaeology, was prompted to research the matter after reading a report on crop circles in an 1880 edition of the science journal Nature.
images from Google Earth's new 1945 overlay, which Jefferys studied for more than 300 hours.
The overlay is a series of photos taken towards the end of World War II by the RAAF and comprises around 35% of the 1945 overlay of England presently available online.
Jefferys points out the material available does not include acknowledged crop circle "hotspots" around Wiltshire.
In a research paper emailed to Huffington Post UK Jefferys writes:
"Using aerial photographs primarily from the Google Earth 1945 overlay, that the number of crop circles appearing each summer has been relatively constant for at least the last 70 years and that these crop circles cannot be explained by the 'hoax theory'. This removal of the validity of the hoaxer's claims means that crop circles remain an unexplained natural phenomenon deserving of serious investigation by academic institutions and other research organisations."Jefferys, who has previously used aerial photography to successfully locate shipwrecks, points out there have been reports of crop circles in the English countryside as far back as 300 years before the period the hoaxers began their work.
In his research Jefferys acknowledges the existence of flaws on the film caused by chemical or mechanical damage to the film on which the 1945 aerial snaps were taken and has taken these into account.
In summary, he says careful examination of the presently available images has yielded 64 shapes that were possible crop circles.
Using a process of elimination to recognise flaws in the negatives, Jefferys selected 13 which conformed strictly to his criteria. (Scroll down to view some of his evidence.)
"The number of circular features that can be reasonably confirmed as crop circles that have been so far found in the survey of the currently available 1945 Google Earth overlay numbers about one dozen. As this survey did not include more than 35% of England and excluded the known crop circle 'hot spots' around Wiltshire the findings are consistent with an annual occurrence of around 100 crop circles across the English countryside in 1945. This, combined with a significant body of historic records describing crop circles, gives the lie to the claims made by various to be the originators and creators of all crop circles. This in turn begs the question 'If not them, then who or what is responsible for the creation of crop circles?'"He told HuffPo UK: "There is a mounting body of evidence that suggests that a rare form of electromagnetic energy called an ionised plasma vortex (generally known as ball lightning) is involved.
"Plasma balls do weird things like passing through solid objects (such as stone walls and glass windows) and floating through the air against the wind. Exactly where this energy comes from and what causes it is not yet understood by science.
"Based on my studies I suspect that the forces involved in the creation of crop circles represent a potentially extraordinary new field of science, a new frontier that could lead to profound discoveries and entirely new technologies.
"Further I believe that if the mainstream scientific community were not so timid and so conservative in their view of the Universe that they would not be sitting on their hands pretending this thing is not happening but would be seriously investigating this unexplained phenomenon."
We're expecting to hear more from Jefferys, who, by the way, is about to embark on a PhD on crop circles, having found a supervisor at the University of Tasmania.