Craig Wright, the Australian who claimed to be the inventor of bitcoin but failed to prove it, is attempting to build a large patent portfolio around the digital currency and technology underpinning it, according to associates of his and documents.

Since February, Wright has filed more than 50 patent applications in Britain through Antigua-registered EITC Holdings, which a source close to the company confirmed was connected to Wright, government records show.

Interviews with sources close to EITC, which has two of Wright's associates as directors, confirmed it was still working on filing patent applications and Britain's Intellectual Property Office has published another 11 patent applications filed by the company in the past week.

"None of this has stopped," one person close to the company said.