The shroud went on display again in Turin on Saturday
As the Turin Shroud is brought out for public viewing again, the BBC's Duncan Kennedy looks at its enduring power to fascinate.
If it was an episode of CSI - Miami, New York or Las Vegas - it would all be solved within a television hour, which, if you strip out the adverts, is about 53 minutes.
The face, the body, the appearance of blood stains, all the clues are there.
And yet, not with the passage of hundreds of years and dozens of inquiries has the mystery of the Turin Shroud been solved to everyone's satisfaction.
So, is it, or is it not the burial cloth of Jesus?
Now, for only the sixth time in a century, the public are getting their chance to don their own sleuthing hats and get a close-up personal view of the main exhibit.
It is the shroud's first display in a decade and more than a million tickets have already been booked to see it by the sceptical, the faithful and the plain curious.
Just over 4.5m (14ft) long and a little over 1m wide, this faded, worn and fragile piece of linen has been the subject of intense debate among scientists, theologians and lay people for centuries.
The material shows the faint image of a bearded man.
For many Christians, it is the face of Christ.
Around the head, there are what seem like the marks of a crown of thorns.
Elsewhere, traces of blood appear to be evident on the hands and feet, indicative, say believers, of Christ's crucifixion.
The first reliable records of the shroud's existence appear to date from the middle of the 16th Century.
It ended up being taken to Turin by Italy's royal family, the House of Savoy, in the late 16th Century.
It was given to the Holy See in 1983.
But credible, scientific doubts about its authenticity surfaced in 1988, when radio carbon dating tests were carried out on small samples of the shroud.
Teams from Oxford University, the University of Arizona and the Swiss Federal Institute of Technology concluded with near certainty, in their view, that the cloth had actually been made some time between 1260 and 1390.
In other words, it was probably nothing more than a clever medieval forgery.
For some, that tainted the mystery of its provenance forever. How could it be the cloth that wrapped Christ's body, if it was made more than 12 centuries after his death?
Others, though, clung to their original conclusions, arguing that the samples used for the carbon dating testing may have been contaminated.
New tests urged
The dissatisfied include Marco Tosatti, a journalist with La Stampa newspaper in Italy, who has just completed a study of the scientific literature on the shroud.
"I believe the 1988 tests were somewhat flawed," he says.
"They didn't use the correct samples and I disagree with some of their calculations."
He goes on to say that no one has successfully reproduced a cloth like the shroud.
"Not even using the laser technology of today has such a unique image been made," he says, "so how could a forger in medieval times manage it?"
Mr Tosatti is not alone in calling on the Vatican to allow further tests to be performed using machinery not available to the three teams of scientists 22 years ago.
The Catholic Church has not responded officially to those requests.
In recent times, the Church has not actually said it is the burial cloth of Christ.
In carefully chosen, subtle, non-committal words, it says that the shroud represents the suffering of Christ.
There was nothing subtle about Adolf Hitler's connection with the shroud.
According to a recent interview with a Benedictine monk, the Nazi leader made it clear he wanted to get his hands on it.
The monk, who gave an interview to an Italian magazine, says that when Hitler visited Italy in 1938, he instructed his top advisers to discuss the shroud. He says they did so with unusual vigour.
When war broke out, the shroud was moved in secret to an abbey in southern Italy.
According to the monk, German soldiers once searched the abbey, but the monks had hidden it in an altar and pretended to be praying in front of it when the Germans came.
Hitler's henchmen went away empty-handed and the shroud was later returned to Turin.
And that is where it will be until mid-May, visible in all its sepia-coloured, less-than glorious, condition.
Science and faith
To enhance the experience, at least according to those behind the scheme, visitors can buy 3D glasses.
The glasses are being sold by the Silesian religious order for a couple of euros though the authorities are less than impressed with this Avatar-inspired innovation.
They say the viewing of the shroud cannot be improved with artificial devices.
With, or most likely without, the 3D glasses, Pope Benedict will be among those to study it. His views on its authenticity are unknown.
"Maybe we will never know," says the journalist Marco Tosatti. "After all, no-one has signed it, like an artist, to tell us what and who it is."
For millions of Christians, that is part of the point.
For them, the Turin Shroud is not about science and proof, it is about belief and faith.
And at a time when the Catholic Church is being buffeted by scandals involving paedophile priests, for some, clinging to that faith is more important than ever.
During the next six weeks a total of more than two million visitors are expected to come and make up their own minds.
For sceptics, it is an interesting relic.
For the committed, it is literally a snapshot of Christ and therefore part of the very fabric of their beliefs.