It was believed by some to have been his burial cloth, but tests done in the 80s indicated it might have been medieval forgery.
The latest tests led by experts have dated the piece back to the first century A.D., indicating it is old enough to have been used for Jesus' burial.
Giulio Fanti, a professor of mechanical and thermal measurement at the University of Padua, announced the studies in a book that was released in Italy on Wednesday. Fanti has studied the shroud for many years, and hypothesized in one paper that radiation could have caused Jesus' bloody face and body to appear on the cloth.
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But it was his most recent study that revealed the time the cloth was made.
He and several researchers from the University of Padua did three test on small pieces of fiber taken from the shroud for the tests conducted in 1988.
In the first two tests, they used infrared light and Raman spectroscopy, and the third test analyzed different mechanical parameters relating to voltage.
They decided that the cloth would have been made between 300 B.C. and 400 A.D.
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Fanti also said that they found trace elements of soil "compatible with the soil of Jerusalem.
"For me the [shroud] comes from God because there are hundreds of clues in favor to the authenticity," he said. But he admited there are "no sure proofs."
Controversy was first stirred by the tests in 1988 that dated the shroud to have been made in the Middle Ages, but it may have been the result of contaminated fibers used to repair it.
Fanti released the book, Il Mistero della Sindone (Mystery of the Shroud), right ahead of Easter when Christians everywhere are celebrating the resurrection of Jesus.
The Shroud is kept in a case in Turin, Italy and is not viewed often, but it will make a televised appearance on Saturday.