Billionaire Robert Brockman, who was indicted in 2020 in what has been called the largest ever tax evasion case against an individual in the U.S., has died. He was 81.

Brockman's death was confirmed Saturday by his lead attorney, Kathy Keneally. Additional details and the cause of death were not immediately available.

His attorneys had been arguing in court that he had dementia and was incompetent to stand trial. But a judge in May ruled him competent and set a February trial date.

Brockman, a Florida native and Houston resident whose fortune Forbes has estimated at $4.7 billion, was the former CEO of Reynolds & Reynolds, an Ohio-based software company that provides solutions to businesses.

In October 2020, the government charged him in a 39-count indictment with evading taxes on $2 billion in gains, wire fraud, money laundering and other offenses. He pleaded not guilty.

The alleged scheme to conceal the billions in income from the IRS spanned decades, the Justice Department said in its announcement of the indictment.

David L. Anderson, the U.S. attorney for the Northern District of California, said at the time that the "allegation of a $2 billion tax fraud is the largest ever tax charge against an individual" in the U.S.

Keneally, a longtime tax specialist who was Brockman’s lead lawyer, was the assistant attorney general in charge of the Justice Department's tax division from 2012 to 2014.

According to court records, the wealthiest Black citizen in the U.S., Robert Smith, Brockman's former business associate, was to be a key witness against him. Smith avoided charges by admitting to evading taxes, paying $139 million in taxes and penalties and agreeing to cooperate, records show. 

At issue in the criminal case against Brockman was the allegation that he avoided taxes through an offshore charitable trust that prosecutors said he secretly controlled — and which he said was independent.

Prosecutors said he used ill-gotten gains to buy a Colorado fishing lodge, a private jet and a 200-foot yacht, among other things. The government filed paperwork last year to seize the 100-acre fishing retreat in the Rockies, The Aspen Times reported then.

It was not immediately clear how Brockman’s death would affect the government’s ability to recover the taxes it says are owed.