An antique-lover is preparing for a huge windfall after an engraving he spotted being thrown into a tip 13 years ago is expected to sell for £20,000 at an auction.

Mat Winter, from Cranbrook, was just 11 years old when he came across the A4-sized black-and-white picture being thrown out with bags of rubbish at his local tip.

He asked if he could take it and kept it in his shed for 13 years before having it valued earlier this year.

It turned out to be the work of German-born Albrecht Dürer, a painter and printmaker regarded as one of the most gifted artists of all time.

Entitled ‘Knight, Death and the Devil’ and completed in 1513, it is one of Dürer's most famous and influential works.

Mat, now aged 24, said: “I’ve had an eye for antiques since I was 10 years old.

“I used to go to the local rubbish tip to see what I could find. I discovered some great stuff.

“One day a lady had some rubbish in her car including the print.

“I thought it looked interesting and asked if I could have it.

“She was more then happy to give it to me because she wanted it to go to someone rather than just throwing it away.

“I was 11 at the time and very happy she let me take it.

“It’s been tucked away in a cupboard at home with all my other antique finds for the last 13 years.

“Recently, I decided to get it checked out to see if it was as special as it looked. I was amazed to find out it was.”

The engraving is expected to sell for between £10,000 and £20,000 but could fetch far more when it goes under the hammer at Rare Book Auctions in Lichfield, Staffs.

Director Jim Spencer said: "I've seen countless prints copying Dürer, from a much later period or produced by a different means, but I'd only ever seen the real thing in museums - until now.

"The owner sent it to me for appraisal.

“I didn't have high expectations when he described how he'd rescued it from someone's car boot at his local rubbish dump around ten years ago.

“I opened the package, removed the bubble wrap and staggered back in awe. My hands were shaking as I held it up to the light.

“The laid paper was absolutely right for the period. The quality of the engraving was exceptional beyond words.

“I knew that only one person could've produced something like this - it had to be the hand of Dürer himself.

"It was simply too good to have been engraved by anyone else.

"With a magnifying glass, we were able to check that every minuscule line matched perfectly.

“It confirmed what we had thought and hoped. This was indeed the real deal.”

A key feature proving the engraving is the work of Dürer is a faint scratch across the head of the knight’s horse.

Mr Spencer added: “I checked our example and the scratch was present. It disappears on later printings, so this sealed it. It was period and authentic.

"It's the most important print I've ever catalogued and offered for sale.”

Mat said he still enjoys searching out antiques at the rubbish tip in Cranbrook and over the years has had to invest in a bigger shed to house all his finds, which includes furniture, china, clocks and more drawings and paintings.

He is planning to get more of the items valued and is hoping to buy a car with his auction money.

The engraving goes under the hammer on September 18.