Twenty-one ancient human skulls have reportedly been stolen from the basement of St. Leonard’s Church, a church in the British county of Kent.

Located in the town of Hythe, the ancient church is renowned for its massive collection of ancient skulls, many of which are put up on display in the church’s ossuary, or bone chamber.

But earlier this week, thieves armed with a bolt-cutter broke into the ossuary and carted away 21 skulls which are believed to be around 700 years old from the display.

The priest-in-charge at the church, Rev. Andrew Sweeney said the crime appeared to have been committed by professional thieves rather than mischievous children or teenagers.

“These people came with the right equipment to break the gate. We believe they came specifically for the skulls. They didn’t take money from inside and there was no vandalism. They just took the human skulls and left,” Sweeney told Kent Online.

Sweeney said he was concerned that the act of skullduggery may have been motivated by a desire to sell the remains on the black market.

“We have always assumed human decency in our visitors and compassion for those whose remains rest in peace in the sacred space of our church. We are saddened that the greed, selfishness or stupidity of some people has destroyed that assumption of common human values.

“We have now had to resort to expensive and complex security measures which we once thought unnecessary,” he added.

Authorities are asking the public to come forward with any information on the macabre theft as according to them, the skulls were part of an important collection that needed to be returned to their rightful place in the crypt.

According to the St. Leonard’s Church’s website, prior to the theft, the ossuary contained some 1,022 skulls which have been the subject of several forensic and anthropological studies.