Italy’s Rai TV broadcast for the first time images of the Turin Shroud, which is revered by many Christians as the burial cloth of Jesus Christ.
The linen cloth bears a faint brownish image of what appears to be a man’s body.
A smartphone app was also created to show digital images of the Turin Shroud.
Pope Francis contributed a message to the broadcast, shortly before he was to celebrate his first Easter vigil.
The newly-elected Pope will preside over a vigil at St Peter’s Basilica on Saturday evening – ahead of the main Easter Sunday celebrations.
Thousands of people from all over the world are expected at Sunday’s Mass.
Viewers were able to watch live images of the 1.21 x 4.42 m Turin Shroud in a 90-minute programme on Rai TV from Turin Cathedral.
The images were also streamed on various websites.
In a video message ahead of the exhibition, Pope Francis said: “It speaks to our heart.”
The Pope described the cloth as an “icon” or an image but was careful not to authenticate as a genuine relic.
His predecessor, Pope Emeritus Benedict, also recorded a video message.
The shroud has never been officially recognized as authentic by the Vatican.
Rigorous scientific testing seems to indicate that the Turin Shroud was woven between 700 and 800 years ago.
But diehard believers say other tests prove that it could have been made at the time of the crucifixion – give or take a couple of hundred years.
The only previous – recorded – TV broadcast of the shroud was in 1973. It was last shown to the general public three years ago when Pope Benedict XVI travelled to Turin to view it.
The Shroud has been kept in the northern Italian city for more than four centuries.
It was taken there by members of the former Italian and French royal house of Savoy who originally acquired it in France in the belief that it had been brought to Europe by returning Crusaders.