Experiments conducted by scientists at the University of Padua in northern Italy have dated the shroud to ancient times, a few centuries before and after the life of Christ.
Many Catholics believe that the 14ft-long linen cloth, which bears the imprint of the face and body of a bearded man, was used to bury Christ’s body when he was lifted down from the cross after being crucified 2,000 years ago.
The analysis is published in a new book, “Il Mistero della Sindone” or The Mystery of the Shroud, by Giulio Fanti, a professor of mechanical and thermal measurement at Padua University, and Saverio Gaeta, a journalist.
The tests will revive the debate about the true origins of one of Christianity’s most prized but mysterious relics and are likely to be hotly contested by sceptics.
Scientists, including Prof Fanti, used infra-red light and spectroscopy – the measurement of radiation intensity through wavelengths – to analyse fibres from the shroud, which is kept in a special climate-controlled case in Turin.
The tests dated the age of the shroud to between 300 BC and 400AD.
The experiments were carried out on fibres taken from the Shroud during a previous study, in 1988, when they were subjected to carbon-14 dating.
Those tests, conducted by laboratories in Oxford, Zurich and Arizona, appeared to back up the theory that the shroud was a clever medieval fake, suggesting that it dated from 1260 to 1390.
But those results were in turn disputed on the basis that they may have been skewed by contamination by fibres from cloth that was used to repair the relic when it was damaged by fire in the Middle Ages.
Mr Fanti, a Catholic, said his results were the fruit of 15 years of research.
He said the carbon-14 dating tests carried out in 1988 were “false” because of laboratory contamination.
The mystery of the shroud has baffled people for centuries and has spawned not only religious devotion but also books, documentaries and conspiracy theories.
The linen cloth appears to show the imprint of a man with long hair and a beard whose body bears wounds consistent with having been crucified.
Each year it lures hundreds of thousands of faithful to Turin Cathedral, where it is kept in a specially designed, climate-controlled case.