A carved block of wood used as a doorstop in a Hertfordshire cottage for over 40 years has sold at auction for £150,000.

The item is in fact a rare Chinese wooden brush pot dating back to the late 18th or early 19th Century, which would originally have been used to store calligraphers’ brushes. It was sold at Sworders’ Asian Art Sale at the company’s Stansted Mountfitchet auction room on April 29.

The owner was unaware of its true value until she took the item to Sworders for expert assessment, and said that the result left her “at an absolute loss for words”. She was present at Sworders’ auction rooms while the auction was taking place, but chose to watch online from the office, rather than from the sale room itself.

Auctioneer and managing director Guy Schooling said: “£150,000 is a life-changing sum for the seller. We initially gave the brush pot a guide price of £30,000-£40,000, but as soon as we shared the details with our network in China, it became clear that interest was going to exceed all expectations.

“In the end, it was bought by a Chinese buyer in the room, against a telephone bidder in China – so it will be returning to the Far East.”

The pot is a rare example of Zitan artwork and is intricately carved from a single piece of wood. The images show dozens of figures in a popular Chinese subject known as ‘The Hundred Boys’ around the outside.

Mr Schooling added: “A result like this only goes to show how easy it is for people to be sitting on a treasure trove at home without realising it.

“We’re always willing to assess items of interest brought in to us for a valuation and have a team of experts in the office, as well as a network of specialist contacts all over the globe, determined to ensure that every item sells for the best possible price.”

Bidding both in the room and online was highly competitive, which led to a number of other spectacular results and high selling prices – including a damaged blue and white Qianlong vase which sold for £56,000, a late 19th Century mirror frame and stand which sold for £20,000, and an early 19th century white jade pendant which went under the hammer for £11,000.

Entries are now being accepted for Sworders’ next Asian Art sale on Tuesday, November 11.