A hacker has hijacked the email account of Bitcoin creator Satoshi Nakamoto, and is threatening to reveal the real identity of the secretive programmer.

In return for 25 Bitcoins, worth more than £7,000, a hacker going by the name of "Jeffrey" wrote on the code repository Pastebin that he would "dox" Bitcoin’s creator, internet slang for unmasking the anonymous.

He told the tech site Wired: "The fool used a primary GMX [Global Mail eXchange] under his full name and had aliases set up underneath it. He’s also alive."

While the hacker posted screenshots that appear to be from Nakamoto’s email account, it is unconfirmed whether he possesses information that could reveal his identity.

In another twist, a message posted from Satoshi Nakamoto’s on the P2P Foundation where the currency was launched account seemed to contradict the hacker’s message.

"Dear Satoshi. Your dox, passwords and IP addresses are being sold on the [private network] darknet," it read. "Apparently you didn’t configure [anonymity network] Tor properly and your IP leaked when you used your email account sometime in 2010.

"You are not safe. You need to get out of where you are as soon as possible before these people harm you. Thank you for inventing Bitcoin."

Since Bitcoin’s rise to prominence as the leading cryptocurrency there has been much speculation about its creator, with some believing the pseudonym covers a group of people.

Most recently the magazine Newsweek published an article wherein a Japanese American called Dorian Nakamoto appeared to confirm he was behind Bitcoin, though in a later piece he denied it.