John McAfee, the founder of the antivirus software McAfee, has died by apparent suicide while awaiting extradition to the United States on tax-related criminal charges.

McAfee, 75, was found dead in a Barcelona jail cell on Wednesday, reported the Spanish publication El País, citing police sources.

The Catalan justice department confirmed McAfee's death to Reuters.

Earlier in the day, Spain's National Court approved the extradition of McAfee to face the U.S.-based charges. 

McAfee, who made his fortune selling antivirus software, had been arrested at Barcelona's airport last October and held in jail while awaiting the outcome of the extradition hearings.

McAfee was accused of evading his taxes in Tennessee by failing to disclose money he made from cryptocurrency and speaking fees, as well as selling the rights to his life story for a documentary. The charges carried a sentence of up to 30 years in prison, according to the Associated Press.

McAfee was fighting the extradition, and claimed to the court earlier this month that he would be forced to spend his life in prison if he was sent to the U.S. Despite being jailed, the outspoken mogul's Twitter account remained active, praising cryptocurrency and railing against his prosecution.

--This post originally appear on Business Insider.

If you or someone you know is struggling with depression or has had thoughts of harming themselves or taking their own life, get help. The National Suicide Prevention Lifeline (1-800-273-8255) provides 24/7, free, confidential support for people in distress, as well as best practices for professionals and resources to aid in prevention and crisis situations.