The discovery was made in mid-January, when Vatican officials and technicians exhumed Pope John's body in a "recognition" ceremony, in anticipation of its transferal from the grotto to the main level of St. Peter's Basilica.

A detailed report on the procedure, drawn up by the officials present, was published by a Venetian newspaper March 24.

The exhumation took several hours, since workmen had to open a marble casing and then three successive caskets: one of oak, one of lead and one of cypress, in which the body was closed.

"Once freed from the cloth that covered it, the face of the blessed (Pope John) appeared intact, with the eyes closed and the mouth slightly open, and bearing the features that immediately called to mind the familiar appearance of the venerated pontiff," the report said.

The body was witnessed by Cardinal Angelo Sodano, Vatican secretary of state, and several others. After it was officially recognized, the body was sprayed with an anti-bacterial agent and the casket was resealed hermetically.

Like other recent popes, the body of Pope John was not embalmed, although it was treated with chemicals so that it could be displayed for the faithful before burial.

The discovery produced considerable surprise among church people in Rome, but Father Ciro Benedettini, a Vatican spokesman, cautioned against reading too much into the finding.

"Objectively, the body was discovered to be preserved. But this does not necessarily mean that a supernatural event was involved," he said.

A Vatican technician present at the exhumation said that in his view there was "nothing miraculous" about the preservation of Pope John's body.

"When he died, some measures were taken for the display of the body for the veneration of the faithful. It also should not be forgotten that the remains were kept in three caskets, one of which was sealed lead," said Nazareno Gabrielli, a technician at the Vatican Museums.

Other experts said that while this type of preservation was unusual, it could be explained by the fact that little or no oxygen could have reached the remains.

Last year Pope John Paul II beatified Pope John XXIII, who is universally remembered for his sense of humanity and for his leadership in convoking the Second Vatican Council.