A FORGOTTEN 18TH century oil painting by a renowned Italian artist will be auctioned for £150,000 after it was found hanging in a family home.

The painting by Canaletto, which depicts the Dogna da Mar building from the San Marco basin in Venice, was hung in a property in Lewes for 50 years.

The owner, who was given the artwork by her mother who purchased it for £100 in 1920, passed away last year and her family decided to sell the piece.

The 18 inch by 12-inch painting was displayed in her drawing room since moving into the Lewes home in 1970.

The Argus: Lost Canaletto painting found hanging in Sussex house is up for £150,000 auctionLost Canaletto painting found hanging in Sussex house is up for £150,000 auction

Although the owner was aware the painting was the work of Italian artist Giovanni Antonio Canal, known as Canaletto, she decided against selling it during her lifetime.

Her family was unaware of its value until expert for Gorringes Auctions of Lewes spotted it on the wall during a routine valuation of antiques.

The artwork has been given a pre-sale estimate of £150,000 and will go on auction on September 28.

Gorringes Auctions of Lewes, in North Street, has had some extraordinary sales over the years, including a lock of John Lennon’s hair (£24,000), George Orwell’s first published book (£82,000) and a Queen Anne 1702 Vigo gold crown (£240,000).

Gorringes Auctions managing partner Philip Taylor said it is an incredibly rare chance for somebody to buy an original Canaletto.

“Bearing in mind fully worked up larger paintings by the artist sell for millions, this is an opportunity for a collector to buy a Canaletto at a relatively affordable price,” he said.

“They just don't turn up on the market. I have been in the business for 50 years and have never come across one before.”

The unsigned painting is thought to have been produced during Canaletto's mature period before he moved to London in the mid-18th century.

The Argus: The artwork has been given a pre-sale estimate of £150,000 and will go on auction on September 28 The artwork has been given a pre-sale estimate of £150,000 and will go on auction on September 28

The back of the canvas is inscribed with the name of Auguste Chatelain, a 19th century Swiss psychiatrist and historian known to have owned at least one other similar work by Canaletto.

It also has a label on the reverse for the Mayfair art dealer Arthur Tooth and Sons, where the late owner's mother originally bought the painting 101 years ago.