It sounds like special pleading, but some assert that other tests on the fabric, as well as historical analysis, suggest it was made at an earlier date. They said, for example, that the results might have been distorted by the presence of fungal biofilms on the cloth, or by damage caused by a fire in the 16th century, or that the region sampled was not representative of the whole. Some critics claimed that the radiocarbon dating was inconclusive. The first historical record of the shroud appears too in the fourteenth century.

The fibres were radiocarbon-dated in three separate laboratories in Oxford, Zurich and Arizona and the paper concluded that, with 95% confidence, the age of the material was medieval: between 12. That was the big deal about the 1989 paper, which analysed small samples taken from one region on the edge of the cloth. And the papal authorities have been unwilling to release samples for scientific study. Kept in the cathedral complex in Turin, it is in the charge of the Vatican, which now cautiously refrains from pronouncing on its authenticity but calls it only an object of veneration. That puzzle persists largely because there has been so little archaeological research on the shroud. If, as some claim, it is a medieval forgery – one of the many faux relics supplying a lucrative market that brought donations to a church in those days – it’s still a profound puzzle. But that’s not to deny what a remarkable and perplexing item it is. I have never seen persuasive evidence that the shroud comes from the time of Christ, and certainly don’t think it is a supernatural phenomenon. On this subject it is only fair to lay your cards on the table at the outset (some efforts to defend the traditional interpretation betray an underlying religious agenda). The Turin Shroud is claimed by some to show the face of Jesus Shrouded in mystery Source: © Hyoung Chang/The Denver Post/Getty Images

Shroud age overrated