It was on Saturday afternoon when the warden of the Church of St Peter and St Paul noticed that a group of boys who had been kicking a ball around had dragged a bollard over to where they were playing, in order to cover up a gaping hole that had suddenly appeared in the grass-covered church grounds.
On closer inspection, the tops of two ancient brick walls could clearly be seen through the deep hole.
"There's a room down there," Father David Carney told The Standard. "I've never known anything like it before. A room underneath our churchyard!
"You can see right down into it – you can see two brick walls there. Nobody knows what it is. It's a mystery."
The hole is too full of earth and other rubbish to be able to see clearly at this stage how large the room is, or what function it may have served.
"I've been asking people at the church if they can throw any light on what it is, and nobody can," Father Carney said.
"I thought it might be a large crypt. Somebody suggested it's a secret tunnel, somebody else suggested a secret room. We are going to get an archaeologist in to try and work out what it is."
The area has now been cordoned off for safety reasons, as the ground around the hole also appears to be subsiding.
Experts will be brought in in the coming weeks to try and solve the mystery.