MADRID—Spanish police recovered on Wednesday a priceless 12th-century religious manuscript known as the Codex Calixtinus, which was stolen from a cathedral last year. The find came a day after four suspects were arrested in connection with the theft, the Interior Ministry said.

The richly-decorated Codex was found in a garage close to the cathedral from where it was taken in the northwestern city of Santiago de Compostela. The tome is considered the first guide for people making the ancient Christian pilgrimage known as the Camino de Santiago, the Spanish name for the Way of St. James.

The find came after police arrested an electrician who previously worked at the cathedral, his wife and son, and another woman on Tuesday. The ministry said police found some (EURO)1.2 million ($1.5 million) as well as other valuable religious works at houses belonging to the detainees.