Buried deep below thousands of tonnes of rubbish on a Welsh landfill site, a hard drive with bitcoin potentially worth more than $100 million (£74m) remains tormentingly just out of reach for James Howells.

The Welsh IT technician, one of the very first bitcoin miners, could today have an eight-figure sum sitting in the bank, but instead he can only watch on helplessly as bitcoin’s spectacular price surge continues.

He began mining the decentralised digital currency - a complex process which involves solving complex algorithms to create new bitcoin - on his trusty Dell laptop after it was released as open-source software in February 2009.

The 32-year-old mined 7,500 bitcoins which he saved in a wallet file on his computer hard drive, only for the device worth millions to eventually end up as landfill after he mistakenly threw it away.

“After I had stopped mining, the laptop I had used was broken into parts and sold on eBay,” he told The Telegraph.

“However, I kept the hard drive in a drawer at home knowing it contained my bitcoin private keys, so that if bitcoin did become valuable one day I would still have the coins I had mined.”

Recalling the subsequent blunder which cost him millions, he explains: “In mid-2013 during a clear-out the hard drive- then worth a few hundred thousand pounds - was mistakenly thrown out and put into a general waste bin at my local landfill site, after which it was buried on site.”

His bitcoin would have been worth around £7.5 million by the end of 2013, and since that fateful day the price of the volatile cryptocurrency has fluctuated wildly. Its price skyrocketed to a record price of $11,000 this week, a 1,000pc rise since the start of the year.

Mr Howells believes that today the value of the bitcoin and other cryptocurrency on the lost hard drive would exceed $107m (£79m), however he hasn’t dwelt on his lost millions.

“I’m not sat here crying about it, accidents happen,” he says. “I just get on with it. I’ve always known bitcoin would go this high and I’ve always known the value of the hard drive would go up.

“In the future I easily see it being worth anywhere from $500m (£270m) to $1billion.”

The digital treasure hunter believes he would have sold a portion of his bitcoins in 2013, investing some in rival currency ethereum, and kept the rest. 

Today, the Newport man, who calls cryptocurrencies the “new gold, oil and water combined”, hasn’t given up on the possibility of finding his buried bitcoin treasure, but first he must get permission from his local council to search the landfill site.

“Digging up a landfill is not as easy as just digging a hole in the ground,” he says. “A modern landfill is a complex engineering project and digging one up brings up all sorts of environmental issues such as dangerous gasses and potential landfill fires, it’s a big, expensive and risky project.”

He adds: “To rebuild the landfill back to the required standards after we have finished excavating is a costly project on its own because four years worth of rubbish has been buried on top since 2013.

“Another issue is that a landfill has never been excavated in the UK before, so we’re in uncharted territory with regards to regulations, local authorities and environmental agencies.”

Mr Howells hopes the increasing value of the bitcoin stash will eventually convince Newport City Council to let him search for the missing hard drive.

He predicts “in the way the steam engine powered the industrial revolution, the next logical step in the connected world is a worldwide internet-based cryptocurrency”.

The Welshman believes he can narrow down the search area considerably by estimating the depth of the hard drive based on the date it was thrown away, while dismissing concerns the data would be unrecoverable due to corrosion.

He says: “The higher the value goes, the more chance I have to recover it, so it's just been a waiting game for the past few years … waiting until the bitcoin price was high enough to make the drive a juicy enough treasure to hunt.”

He is currently invested in Bitcoin Cash, which he says is “gaining momentum at an unbelievable pace” in recent months.

Newport City Council has been contacted for comment.

You can follow James Howells (@howelzy) on Twitter.