DUBLIN — A tip led the police in Dublin to a mummified head believed to belong to an 800-year-old Crusader knight, a week after it was stolen from a medieval church crypt in the city.

The body, known as the Crusader, was the oldest and most famous of several naturally mummified by the dry air and methane-rich soil in the crypt of St. Michan’s, an Anglican church on the north side of the city center. The church, parts of which date to 1095, receives around 28,000 paying visitors a year, many of whom come to see its mummies.

During a break-in over the weekend of Feb. 23 and 24, however, the Crusader was decapitated and the head was stolen. Other sections of the crypt were also desecrated and vandalized, with a nun’s mummified body badly damaged.

The archdeacon of St. Michan’s, the Rev. David Pierpoint, told Irish state radio that he had been shown the head, and another skull that was also recovered, in the local police station. They were both saturated with rainwater, he said, which could cause them to disintegrate after centuries in the unusually dry air of St. Michan’s limestone crypt.