Following a very brief drop in price earlier this week, Bitcoin's valuation is back above the $11,500 mark, so imagine if you had owned 7500 BTC, worth over $85 million, but accidentally threw them away. That was the scenario faced by British IT worker James Howells back in 2013; now, he wants to dig through a landfill site in the hope of finding his missing millions.

Howells was one of Bitcoins early investors. When he amassed the cryptocurrency in 2009, it was almost worthless. After his girlfriend became sick of the noise generated by his constant mining, he gave up digging for more bitcoins.

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

Unfortunately, family life and moving home meant Howells forgot about the hard drive. Then, in mid-2013, it was mistakenly thrown away during a clear-out. It was placed into a general waste bin at his local landfill site, where the drive ended up buried.

By the end of 2013, the coins were worth a few million. Now that their value is closing in on the $100 million mark, Howells has decided to risk landfill gasses and fires to recover his digital wallet key from the site it's occupied for the last five years. Hopefully for him, the drive will still work. "It's a big, expensive and risky project," he said.

A report from Chainanalysis last month estimated that nearly 4 million bitcoins could be lost forever, most of which come from coins mined in the technology's early days when they were almost worthless and people were less vigilant about keeping them, much like Howells.