DUBLIN

In what seems like a surreal subplot from a Dan Brown novel, a number of irreplaceable religious relics have disappeared from churches across the country, the Irish police and a senior cleric say.

The latest in a series of such thefts involved the removal of the preserved heart of St. Laurence O’Toole, Dublin’s 12th-century patron saint, from the city’s historic Christ Church Cathedral. The dean of Christ Church, Dermot Dunne, initially believed the thief had probably hidden in the building when it closed Friday evening, taken the artifact overnight and simply walked out the next morning.

But after scrutiny of closed- circuit video, the police are concentrating on two men who visited the cathedral Saturday morning. Both are believed to be foreign nationals. One of them was carrying a backpack, which, when they left shortly afterward, was being carried at knee-height.

The theft follows similar high-profile robberies from churches, monasteries and convents in recent months, including what are said to be splinters from the cross on which Jesus Christ was crucified and a reliquary that normally contains a jawbone believed to be that of St. Brigid, the female patron saint of Ireland. In the latter instance, the box was empty, as the relic had been removed for cleaning.

In the Christ Church case, there is no doubt the thief — or thieves — knew exactly what to look for. The small cage hosting the heart-shaped box containing the relic was tucked away at the side of a small altar. Christ Church is a major tourist attraction that draws up to 500 visitors a day, even in the off-season.

Although the sale of relics is forbidden by Christian churches, a trade in them appears to be flourishing. Thousands of such relics are for sale on eBay and in many antiques stores and flea markets. However, an item of the prominence of the heart of St. Laurence O’Toole is unlikely to show up at those places.

“’I suppose it would be the equivalent of a prominent piece of art being taken,” Dunne said. “It would likely end up in a private collection. Police have also alerted us to the possibility someone could call looking for a ransom, and we are prepared for that.”