Church kisses goodbye to windfall as Donatello work goes for £3.5m

When the parishioners of San Giovanni Battista church near Padua needed a new organ just over a century ago, they sold a terracotta relief of the Madonna and Child to pay for it.

But however much the organ cost in 1902, the exchange now looks a poor one. For that terracotta relief was by the early Italian Renaissance master Donatello and is now set to sell this month for up to $6m (£3.5m). The work, known as the Borromeo Madonna, after the Borromeo family, who great Italian art patrons and commissioned every major work of art in most of the churches of Padua, is expected to inspire competitive bidding at Sotheby's in New York on 26 January.

There is only one Donatello in a public art collection in the United States and nearly all the others either remain in the churches for which they were made or in major museums in Europe. The provenance of this particular work was lost for many years. It was so covered in dirt and layers of stucco and paint that it was identified only as "circle of Donatello" the last time it came up for auction in 1990 and did not sell. Recent cleaning revealed its beauty while new research established its origins. Anthony Radcliffe, keeper emeritus of sculpture at the Victoria and Albert Museum in London, said it was "distinctly Donatello".

Margaret Schwartz, Sotheby's senior vice-president, said: "Donatello is without question one of the greatest sculptors that ever lived. The present work showcases his extraordinary technique and unique ability to illustrate emotion and realism in a very shallow space. The sale of this masterpiece presents a remarkable opportunity for institutions and private collectors alike." To be fair to the church officials in Padua, they were sufficiently fond of the rare work that they had a copy made in plaster which remains in situ to this day. The copy repeats the exact details of the sculpture, leaving no doubt that the copy was made from this relief.

The original was executed for an earlier church in Lissaro di Mestrino, outside Padua, in about 1450, at a time when the patronage of the church belonged exclusively to the Borromeo family, one of the oldest patrician families in Lombardy.

Donato di Niccolo di Betto Bardi, who came to be known as Donatello, was born in Florence in 1386 and trained in the studio of the sculptor Lorenzo Ghiberti from 1404-07. After several early commissions, he left Florence for Padua. He returned to Florence later in his life, where he died in 1466.

He was hugely important in stimulating the development of realism in Italian painting, notably in the work of the great Paduan artist Andrea Mantegna. This work is said to demonstrate many of the hallmarks of Donatello's style and the figures are similar to those in other, better known works. The way the veil falls over the Madonna's head resembles a terracotta Madonna in the Victoria and Albert Museum, while the Christ child is very similar to the child in the Courajod Madonna in the Louvre in Paris.