The Australian tech entrepreneur who made headlines earlier this week by saying he could prove he was the founder of digital currency bitcoin backtracked from his claim on Thursday.

Craig Wright offered an apology on his blog after failing to deliver on the "extraordinary proof" he had promised would show that he was bitcoin's creator.

Wright did not, however, recant his claim that he was the man behind the pseudonym "Satoshi Nakamoto." It was under this name that someone created the internet-based cryptocurrency in 2008.

"I believed that I could do this. I believed that I could put the years of anonymity and hiding behind me," Wright said. "But, as the events of this week unfolded and I prepared to publish the proof of access to the earliest keys, I broke. I do not have the courage. I cannot."

Concern over veracity of claims

Bitcoin is a web-based currency that allows users to move funds around the globe quickly, anonymously and without the influence of a third party.

Although many tech experts voiced concern over the veracity of Wright's claims, the Australian received more attention that other would-be Nakamotos due to some high-profile support.

Both bitcoin consultant Jon Matonis and lead developer Gavin Andresen made blog posts on Monday endorsing Wright, saying they had been shown convincing proof that the entrepreneur was indeed the currency's creator.

Wright said he had not deceived Matonis and Andresen, but that unfortunately "the world will never believe that now."

es/cmk (AP, Reuters)