Oxford University scientists Wednesday tested a fragment from the Shroud of Turin to determine if it dates from the period of the crucifixion of Jesus Christ.

The tests, using carbon-14 dating, were directed by Professor Edward Hall, head of Oxford's research laboratory for archaeology and the history of art.The 15-foot length of linen, bearing the image of a bearded, crucified man, is venerated by believers who accept that it covered Jesus' body in his tomb. Skeptics consider it a brilliant forgery from medieval times.

Michael Tite of the British Museum said he hoped to get a date with a margin of error of 200 years.

"If 12th, 13th or 14th century, the result is perfectly clear cut," Tite said.

"If we get a date of 100 to 300 A.D. or 200 to 400 A.D., one would start being a bit edgy. Whatever result we come up with, one still has the question of how the image got there," he said.

Similar carbon tests have been done at the University of Arizona and the Federal Polytechnic in Zurich, Switzerland.

The American and Swiss findings are being kept secret until the results of all three tests can be announced together, expected in September from Cardinal Anastasio Ballestrero of Turin.

The Oxford scientists were sent three thumbnail-size fragments of cloth and were not told which of the three was cut from the shroud, which is kept in Turin Cathedral.

Cosmic rays entering the earth's atmosphere create radioactive carbon-14 atoms that are absorbed by all vegetation and thus become part of any material with an organic base, like linen and cotton.

The atoms decay at a known rate, making it possible to estimate how long ago a material absorbed them.