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.