The head of a mummified Crusader has been decapitated from its body and stolen from a crypt beneath a Dublin church.

The crypts at St Michan’s Church contain the mummified remains of Dublin families dating back to the 17th century.

Its most famous occupant is known as the Crusader, a six-foot-six (198-centimetre) soldier lain to rest 800 years ago.

But on Monday, a guide preparing to open the church to visitors discovered the crypts had been disturbed.

Police said thieves had severed the head of the Crusader and taken it with them.

“His legs were pushed up into his torso, his arms were moved to one side and his head has been decapitated,” vicar of St Michan’s and Dublin Archdeacon David Pierpoint told The New York Times.

“His head is gone.”

The crypt was badly damaged, the Church of Ireland said in a statement, adding that the bodies of two other mummies had also been interfered with.

It said the head of a 400-year-old nun was twisted 180 degrees to face the wrong direction, and another mummy had been turned on its side.

The crypts have been closed to the public whilst the theft is investigated.

Dublin Archbishop Michael Jackson implored the vandals to return the Crusader’s head to its rightful place at St Michan’s.

“I am shocked that someone would target this ancient burial place and desecrate the remains of those lying within it,” he said in a statement.

“Not only have these individuals desecrated the sacred crypt but they have destroyed these historic mummies, which have been preserved in St Michan’s for hundreds of years.

“I would appeal to those responsible to examine their consciences and return the head of the Crusader to its rightful place.”

The weekend break-in was not the first time the crypt at St Michan’s had been vandalised.

In an interview with the Irish Times, Archdeacon Pierpoint recalled an incident in 1996 when a group of teenagers took some of the bodies from their coffins and played football with their heads.

“Thankfully at that time the guards did their jobs extremely well and they caught the perpetrators,” he said.

-ABC