A judge cited “persuasive” evidence from lawyer Evatt Tamine about billionaire Robert Brockman’s ability to engage in “sophisticated furtive behaviour to conceal his actions” as a reason why the latter’s criminal trial should go ahead.

United States District Court Judge George C Hanks Jr, dismissing a claim from Mr Brockman’s lawyers that the 80-year-old was unfit to stand trial for tax evasion and other financial crimes because of dementia, said the evidence presented by the US Government supported test results indicating Mr Brockman was “exaggerating his disability to avoid prosecution”.

The judge added: “Much of this evidence came from Evatt Tamine. Tamine is a lawyer who worked closely with Brockman for 14 years and who, according to the Government, helped Brockman conceal assets offshore.”

The Fairylands home of Mr Tamine, an Australian who gained Bermudian status by marriage five years ago, was raided by police assisting the US Department of Justice and Internal Revenue Service in September 2018.

Judge Hanks said: “The law enforcement agents seized more than 90 terabytes of data on about 20 devices, including laptops, desktops, external hard drives, network storage devices, and mobile phones.

“The agents also seized an encrypted private e-mail server, from which they obtained e-mail communications between Tamine and Brockman.”

He said decrypted e-mails between Mr Brockman and his business associates, obtained in the raid, discussed the “falsification, backdating, concealment, and destruction of documents”.

The judge said: “The e-mails seized in the Tamine raid … discuss the use of shell companies and trusts to hide money from regulators.”

He added: “After Bermuda Commercial Bank froze Brockman’s accounts and Tamine began to face increased scrutiny, Tamine sent an e-mail to Brockman suggesting that they establish ‘shell companies’ in an ‘escape jurisdiction’, as well as a ‘hidden fund’ consisting of money held in trust by an Australian lawyer, to help ‘cover [their] tracks’ so that they could avoid ‘disclosing where other accounts are held’ and ‘alerting a regulator as to where they should seek to freeze money’.

“Tamine further stated that, given the ‘fear of detention' he could ‘never again’ travel to the United States ‘with a computer or telephone’” but that he could keep all he needed at the office of a friend and business associate of Mr Brockman, Dr Stuart Yudofsky.

Dr Yudofsky, a neuropsychiatrist whom Mr Brockman first told about his declining cognitive abilities, asserted his Fifth Amendment right against self-incrimination and refused to testify at the hearing to determine Mr Brockman’s competency to stand trial.

Mr Tamine did appear at the competency hearing, where in surprise testimony he said his former boss broke no laws in the US.

Mr Tamine had previously given evidence before a grand jury, which led to Mr Brockman – who is accused of concealing about $2 billion in income from the Internal Revenue Service – being indicted on 39 criminal charges, including tax evasion, wire fraud and money laundering.

Other e-mails discovered during the raid included discussions between the two men about how they could keep government officials, especially customs officers, from seizing laptops and files relating to Mr Tamine’s work for Mr Brockman that Mr Tamine was moving from France to Bermuda.

“Tamine proposed that he use remote access software to transfer files from the drives that were in France to a drive in Bermuda and then wipe the drives that were in France before transporting them,” wrote the judge. “Brockman agreed with the idea …”

The judge said e-mails showed that Mr Brockman wanted to investigate a possible management buyout of Reynolds & Reynolds, the car dealership software firm in Iowa of which he was the CEO and which was owned by a trust.

In an encrypted message, he instructed Mr Tamine – the director of the trustee – to send him an unencrypted letter to make it look like the trustee had asked Mr Brockman to investigate the buy out.

“In effect, Brockman was obscuring his control of the trust with a fabricated letter from the trustee that Brockman himself dictated,” said the judge.

He added that Mr Brockman also told Mr Tamine and another man who worked for him, how to “circumvent machine identification codes” in printer paper and backdate documents.

Judge Hanks concluded: “‘The court concludes that all of this evidence of past sophisticated furtive behaviour is relevant and supports a finding that Brockman is malingering and is competent to stand trial.”