Theguardian_ A rare painting by the 17th-century artist Pieter Brueghel the Younger, described as “exceptional” and one of his largest known works, will be sold by auction in Paris later this month.

The painting was discovered hanging behind a door at a home in the north of France. It had been in the same family since 1900 but its provenance before then remains a mystery.

The work – measuring 112cm high and 184cm wide, and valued at up to €800,000 (£713,000) – is a version of L’Avocat du village (the Village Lawyer), a theme Brueghel reproduced up to 90 times. It is believed to have been painted between 1615 and 1617.

Malo de Lussac of the auctioneers Daguerre Val de Loire, who found the painting during an estimation visit requested by the family, who wish to remain anonymous, said he could hardly believe what he had stumbled across.

“In the family it was known as ‘the Brueghel’ but they had no idea it was a real one. They thought it was a copy; just a bit of decoration that wasn’t worth very much,” De Lussac said.

“When we sent it to Germany for expert verification that confirmed it was a Brueghel and they understood the importance of what they had, they asked us to take a photograph of them in front of the painting that they had lived with for all those years. It was both funny and touching.”

De Lussac added: “It is one of those unique finds that happens once in a career. It’s a very unusual painting in terms of size and the fact it is in exceptionally good condition.”

Pieter Brueghel the Younger, born in Brussels, was the oldest son of the 16th-century Dutch and Flemish Renaissance painter Pieter Bruegel the Elder. His younger brother Jan Brueghel the Elder was also a painter.

Brueghel the Younger painted landscapes, religious subjects – including various depictions of hell – village scenes and flowers but was also a prolific copier of his father’s most popular works.

The Village Lawyer, sometimes known as the Tax Collector’s Office, the Notary’s Office, the Payment of the Tithe or the Lawyer of Bad Cases, is one of his rare original compositions and shows a chaotic scene with villagers queueing up in the lawyer’s chambers, many of them holding gifts including eggs and poultry.

As well as signed and dated versions of this painting, there are also dozens of similar works that are not verified as having been produced by Brueghel or his workshop. An authentic version of the painting dating from around 1617 hangs in the Louvre.

The recently discovered Brueghel will be sold at the Drouot auction house in Paris accompanied by a certificate of authenticity.