The case isn't closed yet on Christendom's most famous relic. A team of investigators from the Università di Pavia got a second crack at the Vatican's dirty laundry, opening up a whole new can of worms.
Back in 1988 an international team announced the Shroud of Turin was 600-700 years old with 95% certainty. The niggling 5% lay in science's inability to duplicate the image, and the shroud's cloth.
The original investigation's protocol called for taking several samples for dating. Luigi Gonnella, the scientific advisor to the Archdiocese of Turin, allowed only one from an outside corner. Instead of dating different sections of the artifact, ensuring the samples were representative of the whole shroud, investigators could only say that corner was from the middle ages.
The problem begins with a fire that badly burnt the relic in 1532, leaving several holes burned on the shroud. Two years later artisans filled them in with a technique called invisible mending. Most likely the tested fibers were from the artisan's repairs, rather than the original cloth. Another circumstance casting doubt on the sample was possible contamination from repeated handling throughout the centuries, skewing the radiocarbon results.
Earlier this year Gianni Barcaccia and pals got their hands on the dust vacuumed off the fibers in 1978, hoping trace the artifact's travels. Over the centuries it's picked up pollen, dust, and other particles from around the globe. Using DNA testing, they've turned up some interesting discoveries. Either the cloth's from medieval times, coming into contact from people from around the world. Or the Shroud of Turin is from the mideast, travelling around the Mediterranean, qne being exposed to different people over a longer time span suggesting it's much older than believed.
Stranger still, Barcaccia and company found data suggesting another hypothesis.
One obvious possibility is that during the course of centuries, individuals of Indian ancestry came into contact with TS. Taking into account the rate of DNA degradation and PCR-biases toward undamaged DNA, the recent contamination scenario is extremely likely. However, one alternative and intriguing possibility is that the linen cloth was weaved in India, as supported perhaps by the original name of TS - Sindon - which appears to derive from Sindia or Sindien, a fabric coming from India.
Check out the full text of Uncovering the sources of DNA found on the Turin Shroud at Nature.