A computer expert committed “forgery on an industrial scale” by telling a “brazen lie” that he is the inventor of Bitcoin, the High Court has heard.

Dr Craig Wright has claimed he is “Satoshi Nakamoto”, the pseudonym of the person widely credited with founding the cryptocurrency.

Dr Wright is being sued by the Crypto Open Patent Alliance (Copa), a non-profit group including cryptocurrency firms, who say that he created an “elaborate false narrative” and forged documents to suggest he was Satoshi and had “terrorised” those who questioned him.

The Australian computer scientist, who attended the start of the five-week trial over whether he was the pseudonymised inventor, has denied the allegations.

On Monday, Jonathan Hough KC, representing the non-profit group, said Dr Wright’s claim “is a brazen lie and elaborate false narrative supported by forgery on an industrial scale”.

He continued in written submissions: “Copa’s case is, simply, that Dr Wright’s claim to be Satoshi is a lie, founded on an elaborate false narrative … As his false documents and inconsistencies have been exposed, he has resorted to further forgery and ever more implausible excuses.”

Mr Hough added: “Dr Wright has consistently failed to supply genuine proof of his claim to be Satoshi: instead, he has repeatedly proffered documents which bear clear signs of having been doctored.”

The original Bitcoin founding document, a white paper named Bitcoin: A Peer-to-Peer Electronic Cash System, was released in 2008, and was authored under Satoshi’s name.

The barrister told the court that despite various efforts by Dr Wright to prove his identity, he had “singularly failed to give that proof”, and that some aspects of his story entered “the realm of farce”.

He also accused Dr Wright of using the artificial intelligence software ChatGPT to forge documents “due to the pressure of time” needed to substantiate his claims.

A key piece of evidence, the court heard, was that experts on both sides agreed that the original white paper was written on OpenOffice software.

But the version provided by Dr Wright as evidence had been found to have been created on software called LaTeX, which did not exist when the white paper was written, Mr Hough said.

Dr Wright first claimed to be Satoshi in 2016 and has been involved in several legal claims against those who have questioned his identity.

His barrister Lord Grabiner KC said Dr Wright had released the white paper after “having spent many years devoted to studying and working on concepts underpinning Bitcoin” and there was “clear evidence” demonstrating his creation of the digital currency.

He said on Monday that Dr Wright possessed “an unusual combination of multi-disciplinary talents” and extensive experience in the field, and Satoshi “uniquely brought these together” in the white paper.

He also said that Copa was “exclusively concerned” with undermining Dr Wright’s claim and that if anyone else was Satoshi, they or their associates would have already come forward.

In written submissions, he added: “This issue has been the subject of extensive media comment since early 2016, as well as multiple sets of legal proceedings in this jurisdiction and elsewhere.

“If Dr Wright were not Satoshi, the real Satoshi would have been expected to come forward to counter the claim.”

“Dr Wright’s use of the Satoshi pseudonym has its roots in his deep admiration for Japanese culture and a desire to maintain a certain level of privacy while developing and ultimately creating Bitcoin,” Lord Grabiner added.

The trial before Mr Justice Mellor, in which Dr Wright is expected to begin giving evidence on Tuesday, is set to conclude next month with a decision in writing at a later date.