Businessman John McAfee, creator of the McAfee anti-virus the software has been charged in the US with conspiracy to commit fraud and money laundering.
Mr McAfee and his bodyguard Jimmy Gale Watson Jr are accused of promoting cryptocurrencies to Mr. McAfee's large Twitter following to inflate prices.
The currencies were then allegedly sold, making the pair $2m (£1.45m), prosecutors said.
The men have not commented on the charges.
Mr McAfee, 75, is currently being detained in Spain in relation to separate criminal charges relating to tax, which he denies. He faces possible extradition to the US.
Mr Watson was arrested in Texas on Thursday.
"Jimmy Watson is a decorated veteran and former Navy Seal. He fought for other people's rights and liberties, and he is entitled to and looks forward to his day in court to exercise some of those very rights," said his lawyer Arnold Spencer.
The strange life of John McAfee
The latest charges were filed in the Manhattan federal court in New York. The pair are accused of buying the cryptocurrency assets before promoting them on Twitter, where Mr McAfee has more than one million followers.
They would then sell the assets as soon as Mr McAfee's endorsements saw prices rise, according to the US justice department and the Commodity Futures Trading Commission.
They allegedly made a further $11m (£8m) in payments from cryptocurrency start-ups for promoting their assets on Twitter, payments which were not disclosed to investors who bought them.
That amounted to having "exploited a widely used social media platform and enthusiasm among investors in the emerging cryptocurrency market to make millions through lies and deception," federal prosecutor Audrey Strauss said.
In the separate tax evasion case - which was announced last October - Mr McAfee is accused of failing to file any tax returns from 2014 to 2018. Prosecutors also say he used other people's names to conceal his assets, including a yacht and property.
Who is McAfee?
A controversial figure, he came to prominence in the 1980s when his company released the first commercial anti-virus software - McAfee VirusScan - and helped spark a multi-billion dollar industry.
Although that business has since been sold to Intel, he still develops cyber-security products of his own.
The entrepreneur, who was born in the UK, also launched unsuccessful bids to become the Libertarian Party's candidate for the US presidential elections in 2016 and 2020.
Mr McAfee has previously expressed his disdain for taxes, tweeting in 2019 that he had not filed tax returns for years because "taxation is illegal".
In 2012, he made headlines after police in the Central American country of Belize investigated the death of one Mr McAfee's neighbors and named him as a "person of interest".
Mr McAfee left the country saying he feared for his own safety. Officials ultimately said he was not a suspect.