A Gloucestershire auctioneer has made a remarkable discovery while exploring a vacant cottage near Stroud.

John Rolfe had not expected to find very much of interest inside the ramshackle property and was astonished when he realised it contained numerous valuable coins.

“It was mind-blowing. I felt like a pirate in a grotto,” he told The Guardian newspaper. “There was a coin here, a coin there. If I opened a drawer there were more coins.” He even found a coin among sugar cubes in a bowl.

The collection, mostly comprising commemorative and specimen coins in mint condition, later sold for £80,000 at Wotton Auction Rooms.

The precise location of the property and the identity of its former owner, who died some months ago, is not being disclosed at the request of his family, but he is believed to have been a former City of London worker with an eye for collectible coinage.

Rolfe said he first heard about the cottage from the solicitors for the family of the deceased.

“When you get a call like that and hear about coins you think it’s going to be a few coppers and maybe a Georgian halfpenny. If you’re lucky you’ll find £20- or £30-worth. I thought it was going to be as dull as dishwater.

“The gentleman was a hoarder. We go into a lot of properties but I’ve never seen anything like it. You could barely get through the front door. We couldn’t turn the lights on. There were boxes and boxes of paperwork floor to ceiling in every room. A normal house clearance will take a day or two. This took three weeks of four men every day.”

Rolfe added that while the cottage was damp and decaying the coins were in excellent condition; many still sealed in plastic with their original receipts.