Doubts have been cast on computer scientist Craig Wright's claim that he created the digital currency Bitcoin.
The 45-year-old Australian says he is the person who has until now gone by the name of "Satoshi Nakamoto".
In 2008 "Satoshi Nakamoto" published a paper explaining how to create the virtual currency.
Mr Wright has spoken to the BBC, The Economist and GQ magazine. He also published a blog post to support his claim.
In the interviews and in the blog he offered a piece of text encoded with what he claims was the private encryption key used to sign the original 2008 paper.
He told the BBC: "I was the main part of it, but other people helped me.
"Some people will believe, Some people won't, and to tell you the truth, I don't really care."
He says he has come forward now because, "I care so passionately about my work, and also to dispel any negative myths and fears about Bitcoin".
"I cannot allow the misinformation that has been spread to impact the future of Bitcoin and the blockchain." The blockchain is a shared database of all transactions on the Bitcoin network.
Last year Wired magazine and Gizmodo identified Mr Wright as the possible creator of Bitcoin. It also said he had hundreds of millions of dollars of the digital currency.
Police later raided Craig Wright's Sydney home and office, on behalf of the Australian Tax Office.
Police said at the time the raid was not related to the Bitcoin stories.
The Australian Tax Office has declared that Bitcoin was an asset, rather than a currency, and therefore was taxable for capital gains purposes.
Among those who are convinced is Gavin Andresen, the chief scientist of the Bitcoin Foundation.
He has written a blog in which he says he had a private meeting with Mr Wright in London.
"After spending time with him I am convinced beyond a reasonable doubt: Craig Wright is Satoshi."
He says part of their meeting was spent on a "careful cryptographic verification of messages signed with keys that only Satoshi should possess."
However the University of Surrey's Professor Alan Woodward told Forbes: "His blog proves very little."
"He claims to be displaying proof that he has the private key for some early transactions... but no one seems to be able to decode the key to prove it independently."
The Economist was not entirely convinced.
"Our conclusion is that Mr Wright could well be Mr Nakamoto, but that important questions remain."
The Economist added: "It may never be possible to establish beyond reasonable doubt who really created Bitcoin."
Whoever is the real Satoshi Nakamoto is worth a large sum of money… virtual or real. It is believed they have one million Bitcoins. At current market value they would be worth around US$400 million (NZ$570 million) at present rates.