A priceless, religious sculpture has been left “looking like a Disney cartoon” following a botched restoration attempt at a northern Spanish church.

The wooden carving of St George on horseback has been a feature of the Romanesque church of San Miguel de Estella, in Navarre, northern Spain, since the 16th century.

But efforts by the church’s priest to return the sculpture to its former glory ended in disaster when a local schoolteacher was enlisted to transform the artwork.

Mayor Koldo Leoz said the restoration was ordered without the consent of the town’s authorities, and it would be “unfair” to call the work a “restoration”. He said the attempt had caused an “irreparable loss” of the original piece.

“How is it possible that the parish priest of a church is able to decide the fate of a 16th century statue without communicating his intentions either to the city council or to the local government and ignoring absolutely his legal duty or professional judgment?” he wrote on Twitter.

“I do not doubt the good will of both the pastor and the person in charge of desecrating this work of art through inappropriate techniques, but the negligence of both is very serious and cannot overlap with the excuse of goodwill.”

He added: ”Today Estella is not in the news for its spectacular historical, artistic, architectural and cultural heritage in general, it is there because of an unfortunate intervention on a 16th century San Jorge carving in one of the imposing religious temples in the city.”

The once muted carving, that shows St George on horseback, battling a dragon, has now been transformed with bright paint colours, with commentators comparing the updated sculpture to a Disney cartoon and a Playmobil character.

The story draws echoes with the botched restoration attempt of Ecce Homo in 2012, a religious mural in the northeastern Spanish town of Borja, that left Christ looking disfigured.