The women belong to a group of nuns who broke with the Catholic Church last year when they publicly declared that they no longer recognize the authority of the Pope.
The Archbishop of Burgos has requested that the nine sisters of the Order of Saint Clare leave the 15th-century convent they lived in, as they no longer have the right to use church property after their excommunication.
But the nuns have refused to move, and have appealed a court decision from last summer that sided with the archbishop.
On Thursday, two of them were arrested on suspicion of “embezzlement of cultural heritage.” An antique dealer suspected of having purchased the objects was also detained. On Friday, it was announced that they would be released pending further investigation.
"We have committed no crime and we have nothing to hide," the nuns wrote in a statement via social media.
After breaking with the Catholic Church, the women have joined Pablo de Rojas, a previously excommunicated ultra-conservative priest who claims that all popes since Pius XII (who died in 1958) have been appointed illegally.
