Sam Bankman-Fried’s lawyer said on Tuesday that a suggested 100-year prison sentence for the FTX founder would be “grotesque” and “barbaric” and at most a term of a few years behind bars would be appropriate for crimes that the disgraced cryptocurrency mogul still disputes.

In pre-sentencing arguments filed just minutes before a late Tuesday deadline in Manhattan federal court, attorney Marc Mukasey said a report by probation officers improperly calculated federal sentencing guidelines to recommend a sentence just 10 years short of the maximum potential 110-year sentence. Bankman-Fried, known for his casual clothing and wild hair, was convicted of seven counts of wire fraud and conspiracy to launder money in November.

A spokesperson for prosecutors, who will respond in court papers in mid-March, declined to comment. Mukasey noted, however, that prosecutors had agreed with the 100-year recommendation and said it was supported by trial evidence.

On 28 March, Judge Lewis A Kaplan will sentence the man prosecutors say cheated investors and customers of at least $10bn in businesses he controlled from 2017 through 2022.

Bankman-Fried’s FTX trading platform was perceived by some in the cryptocurrency industry as a pioneer before it collapsed into bankruptcy in November 2022, weeks before he was brought to the United States from the Bahamas for trial.

Mukasey wrote on Tuesday that the probation office miscalculated federal sentencing guidelines to justify its recommendation. A proper sentence, Mukasey said, would be based on guidelines that would call for between five and six and a half years in prison, at most.

When Bankman-Fried’s charitable works and his commitment to others were considered, an appropriate sentence would return him “promptly to a productive role in society”, the lawyer said. Mukasey signed the 90-page document that was also worked on by four other lawyers.

Mukasey said that the probation office “recommends that the Court sentence Sam to 100 years in prison. That recommendation is grotesque.” He called on the judge to reject the “barbaric proposal” for a “brilliant, complex and humane person” who does not use drugs, rarely drinks and is a first-time offender.

“Sam is not the ‘evil genius’ depicted in the media or the greedy villain described at trial,” Mukasey wrote. “Sam is a 31-year-old, first-time, non-violent offender, who was joined in the conduct at issue by at least four other culpable individuals, in a matter where victims are poised to recover – were always poised to recover – a hundred cents on the dollar.”

FTX was once the world’s second-largest crypto exchange, worth about $32bn in 2022, and Bankman-Fried seemed to be flying high with the purchase of Super Bowl advertising and endorsements from celebrities including the comedian Larry David and NFL superstar quarterback Tom Brady.

After his arrest, though, Bankman-Fried’s communications were found by the judge to be attempts to influence trial witnesses and he was jailed before trial. For more than a half year, Bankman-Fried was permitted to live at home with his parents – both Stanford Law School professors – in Palo Alto, California, where he grew up. The judge revoked Bankman-Fried’s bail after finding it likely that he leaked the diary of the prosecution’s star witness, his former business and romantic partner Caroline Ellison, to the New York Times.

Mukasey said the media portrayal of Bankman-Fried as a luxury-laden billionaire who craved wealth was wrong and he included a quote from his client’s father, who said: “For anyone who knows Sam, the popular portrayal of him as a high-rolling, celebrity-seeking, CEO driven by greed is simply bizarre.”

Mukasey also quoted Bankman-Fried’s mother, who said her son “has been racked with remorse for not having prevented the implosion of FTX and the damage that followed. It is, he has told me, the first thing he thinks about when he wakes up and the last thing he thinks about when he goes to sleep.”

Mukasey wrote that Bankman-Fried “does not feel pleasure, or happiness, or joy, even when something very good happens to him”, and that he was diagnosed in college with anhedonic depression and has been on antidepressant medication ever since.

Mukasey wrote that Bankman-Fried, regardless of his sentence, will never be totally free.

“He will be scorned by many people wherever he goes for the rest of his life,” he said.