Some scholars have suggested that the writing is from a reliquary attached to the cloth in medieval times. But Dr Frale said that the text could not have been written by a medieval Christian because it did not refer to Jesus as Christ but as “the Nazarene”. This would have been “heretical” in the Middle Ages since it defined Jesus as “only a man” rather than the Son of God.

Like the image of the man himself the letters are in reverse and only make sense in negative photographs. Dr Frale told La Repubblica that under Jewish burial practices current at the time of Christ in a Roman colony such as Palestine, a body buried after a death sentence could only be returned to the family after a year in a common grave.

A death certificate was therefore glued to the burial shroud to identify it for later retrieval, and was usually stuck to the cloth around the face. This had apparently been done in the case of Jesus even though he was buried not in a common grave but in the tomb offered by Joseph of Arimathea.