A top court in Spain on Thursday remanded in custody anti-virus software creator John McAfee pending a decision on his extradition to the United States where he is wanted for tax evasion.
The 75-year-old has been held at a prison near Barcelona since he was arrested in the Spanish city in October just as he was about to board a flight to Istanbul.
His arrest followed his indictment in June in the United States for tax evasion and wilful failure to file tax returns between 2014 and 2018, despite earning millions from consulting work, crypto-currencies and selling the rights to his life story.
If convicted, he could face up to 30 years in prison.
Spain's National Court rejected McAfee's appeal against his remand in custody, arguing that given the lengthy prison sentences he is facing there was a "serious risk" he would seek to escape justice as he has in the past.
His wife Janice has said on Twitter that he is "not doing well" and had faced delays in getting "proper medical care" in prison but the court said he had "ailments which are typical for his age" and was getting treated.
Since making a fortune with his eponymous antivirus software in the 1980s that still bears his name, McAfee has become a self-styled crypto-currency guru.
He has one million followers on Twitter, where he describes himself as a "lover of women, adventure and mystery".
McAfee made headlines after he moved to Belize and his neighbour in the Central American country was mysteriously murdered in 2012, a crime that remains unsolved.
When the police found him living with a 17-year-old girl and discovered a large arsenal of weapons in his home, McAfee disappeared on a month-long flight.
The dead neighbour's family later filed a wrongful death suit against McAfee and last year a court in Florida found against him, ordering him to pay the family more than $25 million.
In 2015, McAfee was arrested in the United States for driving under the influence. He again disappeared from view until January 2019, when he fled the country.