Dariusz Dreksa and his wife had been working on the house near the city of Opole when they came across the 16th century manuscripts decorated with a wooden cover and adorned with leather and metal finishes.
Mr. Dreksa told local news website Opole24: “While browsing the first page and comparing it with information on the Internet, my wife and I decided that it could be the Brzesko Bible from 1563.
“We immediately notified the conservator of monuments who later came to collect them.”
Taking their name from the city of Brest, now in modern day Belarus where they were produced through the efforts of prominent Polish-Lithuanian nobleman and Protestant reformer Mikołaj Radziwiłł, Brest Bibles were the first complete Polish translation from Hebrew and Greek.
Printed mainly for Protestants most were later destroyed during the Counter Reformation with only 20 to 40 copies surviving.
Sławomir Marchel, director of Poland’s State Archives in Opole, told the Polish Press Agency: “We do not know how the copies of the Brest Bible, published in the 16th century by one of the [Mikołaj] Radziwiłłs, ended up in Upper Silesia and why someone hid them in such a way.
“However, we can speak of a great dose of luck that these 400-year-old books, despite such difficult conditions, have survived to our times.
“This discovery is certainly a kind of sensation on a national scale.”
He added: “Everything we see indicates that this copy is identical to those that we have in the country confirmed as 16th-century.
“Even the paper, the way of publication and the fittings indicate that it is very valuable.”
Delighted finder Mr. Dreska said: “My wife and I are incredibly pleased that we were able to find such a treasure at home.”
Experts now plan to carry out further analysis to confirm their authenticity.