When the National Museum of Ireland received two 4,000-year-old ax heads, carefully wrapped in styrofoam inside a cereal box, from an anonymous source, it appealed for more information. The objects are “of outstanding importance and impressive”, the museum said, but experts needed to know more about exactly where they were found.

Now they have their answer, according to TheGuardian: a County Westmeath farmer has revealed himself as the mystery sender, claiming he made this “crazy” discovery using a metal detector on his farm.

Thomas Dunne reported finding the objects by chance on fresh grass at Banagher, late June. “One day, I was cutting fresh grass to feed the calves and a piece of metal fell out of the cutter,” he told the Irish Times.

“Then we started looking for it because we were afraid it would get stuck in the harvester and break it. So I got someone with a metal detector to look for it and that’s how we found them. It was under some beech trees. There must have been ancient forts in the surrounding area.”

It is illegal in Ireland to search for archaeological objects using a metal detector unless written permission has been granted. Penalties can range from three months in prison to a fine of €63,486. Of course, no penalty will be imposed on Dunne.

When the museum anonymously received the ax heads, it appealed for more information, saying it was “critical to know the exact location where they were found” because they may have had a “ritual or metaphysical use”. Any information, it said, “would be treated confidentially and used only to supplement information related to the discovery of the item.”

Archaeological finds in Ireland without a known owner become the property of the state and, as part of the country’s heritage, are preserved in national or certified museums for future generations.