Craig Wright, the Australian computer scientist who says he invented bitcoin under the pseudonym Satoshi Nakamoto, has denied forging documents to support his claim. In his first day of giving evidence at the high court in London on Tuesday, Wright denied any forgery or falsification and attacked the qualifications of his own expert witness who found otherwise. The hearing was part of a lawsuit brought by Copa, a coalition of cryptocurrency-linked tech firms, which is seeking to invalidate his long-held assertion that he is the real Nakamoto. Copa is asking the high court for a “negative declaration” that Wright is not Nakamoto, and says such a ruling would stop him challenging people seeking to develop bitcoin-related projects. Jonathan Hough KC, the coalition’s barrister, asked Wright: “Have you ever forged or falsified a document to support your claim to be Satoshi Nakamoto?” Wright replied: “No.” Hough asked: “Have you ever knowingly presented a forged or falsified document to support your claim to be Satoshi Nakamoto?” Wright said: “I have not.” On the first day of the trial, Copa presented evidence that it said proved otherwise, and it called Wright’s claim a “brazen lie”. But over the course of a day’s questioning, in a courtroom so hot and stuffy that Wright’s barrister criticised the “extremely oppressive” conditions and pleaded to have the hearing moved to a different room, Wright rejected each allegation. One document, supposedly written by Wright before the publication of the bitcoin white paper that introduced the cryptocurrency to the world, contained passages referring to the currency in the past tense because of a “shared environment where a completely different file, unrelated to the earlier research, has been merged”, he said. Another document, again dated before the publication of the white paper, contained references to four academic articles published some time later because “researchers share” pre-publication, Wright explained. He said a third document, produced in two versions, one that appeared to support Wright’s claim and one that did not, had been altered in the latter case only. He said misaligned numbers in the former document could be explained by an error in printing rather than a problem with the pdf itself. “If I had forged that document then it would be perfect,” Wright said. “If you go into Adobe, there’s not going to be a font error.” Wright’s explanations for discrepancies occasionally contradicted those posited by expert witnesses for both sides. Asked why his “nonspecific hearsay” was different from “two independent experts in this case”, Wright demurred, saying: “I don’t see them as terribly independent.” He raised concerns that Dr Simon Placks, the expert appointed by his own solicitors, was under-qualified for the task. “I didn’t choose Dr Placks, I didn’t want Dr Placks,” Wright said. “Dr Placks is a psychologist. He has a degree in psychology. He has no qualifications in information security.” Asked if his position was that “the expert called by your side is not a suitably qualified expert to give evidence on what he covers in his reports”, Wright said: “If you’re asking me that directly, yes.” After viewing evidence provided in the form of a video of Wright filming a computer monitor, Wright was asked why he never once filmed himself interacting with the screen. He explained that “you have to put down your phone and move around”. Asked whether he couldn’t operate a mouse and a phone at the same time, he said: “And hold the thing still? No.” Shown a later video in which he did interact with the screen, Wright explained: “I don’t like doing it. The fact that I can try doing it doesn’t mean I like doing it.” The trial is expected to conclude next month and the judge will issue his decision in writing at a later date.