22kg slab of ancient 'bog butter' discovered on Donegal farm

The large block of butter was discovered in a field in West Donegal. Picture: NW Newspix

A slab of butter believed to be hundreds of years old has been uncovered by '"pure luck" on a Donegal farm.

The ancient butter was unearthed while work was ongoing at Micheál Boyle's farm at Loughfad, Portnoo.