Shawn Pogatchnik / AP

The iron cage that housed the heart of St. Laurence O'Toole sits broken and empty on Sunday.

Irish police on Monday were searching for a heart-stealer, with a twisted love of history.

Officials at Christ Church Cathedral in Dublin said they're distraught and perplexed over the theft of the church's most precious relic: the preserved heart of St. Laurence O'Toole, patron saint of Dublin.

O'Toole's heart had been displayed in the cathedral since the 13th century. It was stored in a heart-shaped wooden box and secured in a small, square iron cage on the wall of a chapel dedicated to his memory. On Saturday someone cut through two bars, pried the cage loose, and made off with the relic.

"I am devastated that one of the treasured artifacts of the cathedral is stolen," said the Most Rev. Dermot Dunne, the cathedral's dean. "It has no economic value but it is a priceless treasure that links our present foundation with its founding father."

Ireland's national police force, the Garda Siochana, said detectives were studying hours of closed-circuit TV footage to try to identify the approximately 40 people who walked out the cathedral's front doors Saturday morning.

 “Nobody has ever attempted to steal the heart in the past; it was just there and it never crossed my mind that it might be stolen,” Dunne said. “It has no monetary value but we have loads of silver. It's the last thing we thought would be stolen.”

The police said the thief may have hidden overnight in the cathedral and fled with the heart when its doors opened Saturday. Worshippers didn't spot that the relic was missing until Saturday afternoon. Nobody was arrested.

The Irish Independent reported that the thief apparently lit two candles during the night before making off with the relic the next morning.

"The vergers realized it was gone when they opened the cathedral at 9.30am on Saturday morning," Dunne said.

Shawn Pogatchnik / AP

Tourists and vehicles pass by Christ Church Cathedral, one of the landmark buildings in Ireland's capital city.

"It was definitely there the evening before. They also noticed that there were two peace candles lit on the Trinity Altar. It's all very strange."

Ireland's churches have suffered a spate of such robberies of irreplaceable, but also hard to sell, religious artifacts.

Last year three relics believed to be fragments of the cross used to crucify Jesus were stolen from Holy Cross Abbey in County Tipperary. Police safely recovered those relics in January but arrested nobody.

St. Brigid’s jawbone?

Also in January, a thief stole the ornate container housing the jawbone of St. Brigid in a northside Dublin church. The container, called a reliquary, was bolted down to the altar. However, it had just been cleaned and so the jawbone of St. Brigid, one of Ireland's earliest and most venerated saints, wasn't inside.

O'Toole was Dublin's archbishop from 1162 to 1180 and gained a reputation as a skillful mediator between rival Gaelic and Norman factions then fighting for power in Ireland. He died aged 58 while traveling in Normandy on another peace mission. On his death bed he was said to have declined to make a will, claiming not to have a penny to his name.

Pope Honorius III canonized O'Toole in 1225 on the weight of many claims of miracles at his original grave site.

O'Toole's heart had been the last surviving part of his remains. His bones were reinterred in an English church yard in 1442 but were dug up and disappeared during the Protestant Reformation of the 16th century.

Although O'Toole is mainly revered by Roman Catholics, Christ Church Cathedral has been a center of worship for the Anglican-affiliated Church of Ireland since the Reformation.

The Associated Press contributed to this report.