Some say it has mystical powers derived from its ancient origins as an Aztec symbol of death. Others believe is it one of 13 crystal skulls that will foretell the destiny of humankind when brought together in the same place.

Whatever legends are attached to the crystal skull of the British Museum in London, there is one indisputable fact. No other single object in the museum's extensive collection has acquired such a cult following from New Age devotees.

Now, however, science can finally set the record straight and in doing so shatter one of the most enduring myths of an object steeped in historical fantasy. The crystal skull is a fake.

A detailed analysis of the crystal skull's surface has revealed that it was cut and polished with the sort of rotating wheel common in the jewellery houses of 19th Century Europe but absent in pre-Columbian America.

Historians and scientists believe that the crystal skull was cut from a piece of Brazilian rock crystal by a lapidary in Europe, possibly Germany, and then sold to collectors as a genuine relic from the ancient Aztec civilisation of Mexico.

Doubts about the authenticity of the crystal skull - a near life-sized sculpture - first surfaced more than a decade ago. Tests have now confirmed that it is almost certainly not a genuine Aztec object, said Professor Ian Freestone of the University of Wales at Cardiff and former head of scientific research at the British Museum in London.

"We are not at all sure that there is a rock source in Mexico that would produce a rock crystal of this size. There is strong circumstantial evidence that it comes from Brazil," Professor Freestone said.

"When you look at known, genuine Aztec rock crystals, they have a much gentler polish. This has the harsh, polished look you get with modern equipment," he said.

These two findings alone do not prove a fraud, but it was when scientists began to investigate the surface of the skull under a powerful electron microscope that the doubts about the skull's origins began to be confirmed.

The scientists took impressions of the skull with the same flexible resin used by dentists to take precise impressions of teeth. This revealed the minute rotary scratch marks around the eye sockets, teeth and cranium and was clear evidence that the sculpture had been cut and polished with a wheeled instrument - and the Aztecs did not have the wheel.

"The evidence coming together suggests that it was late. To me the case is overwhelmingly against it being of earlier, Aztec origin," Professor Freestone said.

Further work by archivist Jane Walsh of the Smithsonian Institution in Washington points the finger of suspicion at Eugene Boban, a 19th Century collector of pre-Columbian artifacts who appears to have been instrumental in selling at least two crystal skulls purporting to be of ancient origin.

Not much is known about Boban except that he was a French citizen who spent more than two decades of his life in Mexico, Dr Walsh said.

Documents unearthed by Dr Walsh reveal that it was Boban who had acquired the skull that eventually ended up being sold in 1897 by Tiffany's, the New York jewellers, to the British Museum.

She also found that it was Boban who some years earlier had attempted to sell the same skull to the Smithsonian Institution. And it was Boban who sold a similar crystal skull to a collector who later donated it to the Musee de l'Homme in Paris, where it exists today.

For Boban to come into possession of two crystal skulls purporting to be of pre-Columbian origin may be a coincidence too far, especially in the light of the new scientific evidence suggesting a fake.

Colin McEwan of the British Museum said that the skull, which is going on display this Christmas in the museum's Wellcome Trust Gallery, has been the subject of some peculiar rituals over the years when it was in the Museum of Mankind.

"We had people going into seances and talking in tongues," Dr McEwan said.

One native American legend tells of the existence of 13 such skulls which are supposed to contain information about the origins and destiny of humankind. At a time of great need all the skulls would be rediscovered so that they can be brought together in one place to reveal their secrets, so the legend goes.

Interestingly, there are now about a dozen large crystal skulls known to exist in the world, and all but three of them are in private hands.

Some of those who believe in these legends have accused the museum of trying to hide the skull from public view, or of "trapping" the cosmic energy contained in it, Dr McEwan said.

"We've had extensive petitions claiming that damage has been done to the object because it has feelings, it's imprisoned, it's not allowed to fulfil its destiny, and so forth," he said.

The fact that the skull is not Aztec but probably a 19th Century fake will of course not be welcome news to those who adhere to its more ancient origins, but it is unlikely to dissuade them of its authenticity.

"They just don't believe that. They believe the museum has an agenda which is antithetical to their beliefs and interests," he said. Professor Freestone also accepts that the latest findings are unlikely to convince those who believe that the crystal skull is anything but a fake.

"As soon as we say that one part of it has been polished in a certain way, someone else says it's because it's been touched up later on. It's hard to make a cast-iron case, to be honest," admitted Professor Freestone.

"You've only got to look at the shroud of Turin to see that some people will be hard to convince even in the face of overwhelming evidence," he said.

Nevertheless, even if it is a fake, the crystal skull in London still commands a lot of interest from members of the public. As Professor Freestone says: "Whatever you think of it, it's a fantastic object. Even if it was made in Germany at the end of the 19th Century."

Joshua Shapiro, an author who believes the crystal skull has mystical properties, said it was difficult for him to comment on the British Museum's findings.

"It sounds like they wish to discredit the signifance of their crystal skull and the possibility that it could have been carved or fashioned by the Meso-American people in Mexico where it was purportedly discovered," he said. "These questions might not even be as important as what this crystal skulls represent within this field of study... Even if its origins or who made it is unknown, it helped to give people in the world an awareness that such objects do exist, and that they are revered by the indigenous people in the world."