The founder of the popular McAfee antivirus software has been found dead in a prison cell in Barcelona, awaiting extradition to the United States.

Local media are reporting John McAfee was found dead in Barcelona while awaiting extradition on tax evasion charges in the US.

McAfee was arrested in October at a Spanish airport en route to Turkey on a request from the US Justice Dept.

In recent years McAfee had grown into a larger-than-life character after amassing a more-than $100m fortune on his sale of the anti-virus company. 

The 75-year-old was a crypto enthusiast and conspiracy theorist.

If he had been extradited, he was facing up to 30 years in jail.

He long believed the government was out to get him and two years ago tweeted that “if I kill myself I didn’t.”

McAfee owned 9 homes and a fleet of planes before the 2009 financial crisis when he was hit hard.

He liquidated much of his assets and moved to Belize where he became increasingly unhinged, touting conspiracy theories and eventually going into hiding.

Popular antivirus software

McAfee primarily develops digital security tools for personal computers and server devices, and more recently, for mobile devices.

McAfee brands, products and sub-products include:

• IntruShield
• McAfee Change Control
• McAfee DAT Reputation^[19][20]
• McAfee E-Business Server
• McAfee Entercept
• McAfee SiteAdvisor
• McAfee VirusScan