It is the holiest of Christian relics; a simple linen cloth that was used to wrap Christ's body after he was crucified and which bears the imprint of his face.
But in 1988 a group of scientists used carbon-dating techniques to conclude that the Turin Shroud was nothing but a medieval hoax.
Now one of the scientists involved in the original tests has sensationally changed his mind and admitted that the shroud could be far older than previously thought.
Ray Rogers, who died of cancer in 2005, was a director of the Shroud of Turin Research Project (STRP) that analysed the yellowing linen cloth.
Mr Rogers and a team of scientists carried out tests on a tiny section of the Turin Shroud and declared that it had been produced approximately 1300 years after Jesus was born.
But in a new documentary, a video message from Mr Rogers shows that he may have changed his mind.
In a video filmed shortly before his death Mr Rogers says: 'I don’t believe in miracles that defy the laws of nature. After the 1988 investigation I’d given up on the shroud.
'But now I am coming to the conclusion that it has a very good chance of being the piece of cloth that was used to bury the historic Jesus.'
The shroud was mended after a fire in the Middle Ages and Mr Rogers believed the 1988 tests were invalid because they were carried out on a repaired section of the shroud rather than the original linen.
When the original 1988 results came back some of those who believed in the shroud said tha tthe carbon-dating had been carried out on a newer section of the cloth.
Among these believers were amateur scientists, Sue Benford and Joe Marino, from Ohio who said that the shroud had been repaired with 16th century cotton.
Mr Rogers said: “I’d read these things by people from the lunatic fringe explaining why the date was wrong. I was irritated and determined to prove Sue and Joe wrong.”
But after examining the fibres taken from an earlier investigation in 1978, Ray was shocked to find cotton present too.
He said: 'The cotton fibres were fairly heavily coated with dye, suggesting they were changed to match the linen during a repair.
'I concluded that area of the shroud was manipulated by someone with great skill.
'Sue and Joe were right. The worst possible sample for carbon dating was taken.
'It consisted of different materials than were used in the shroud itself, so the age we produced was inaccurate.'
Some sceptics have accused Ray Rogers of 'starting with the desired conclusion and working backward to the evidence.'
But Phillip Ball, the former editor of Nature magazine, which published the 1988 carbon-dating research has staunchly defended Mr Rogers, saying he had a history of 'respectable work'.
The Turin Shroud was first re-discovered in May 1898 when a negative photograph of the cloth showed the startling image of a man's face.
Last week evidence was published that the shroud had been secretly guarded by the Knights Templar following the sacking of Byzantium, now Istanbul, in 1204.
It then resurfaced in Lirey, France, in 1353, when it was displayed in a church by descendants of Geoffroy de Charney, a French Templar knight burned at the stake.
The cloth is kept in the Cathedral of Saint John the Baptist in Turin and will next be publicly displayed in 2010.
(Original headline: Turin Shroud COULD be real, says scientist who originally said it was a medieval fake )
