John McAfee, the controversial antivirus software magnate who’d had multiple recent run-ins with the US law, has died at 75. McAfee was awaiting extradition in a Spanish prison after being charged with tax evasion in the United States last year. McAfee was found dead in his cell in a prison near Barcelona on Wednesday around 1 p.m. ET and a medical examiner went to the scene, a spokeswoman for the Superior Court of Catalonia told CNN. She said the cause of death is under investigation. A statement from the Catalonia regional government Justice Department, which manages prisons there, said that prison medical personnel and guards attempted to perform life-saving procedures after finding McAfee, but were unsuccessful. The statement said “everything indicates” that McAfee could have died by suicide. His death came after a ruling from a three-judge panel at Spain’s National Court in Madrid this week that McAfee could be extradited to the United States to face charges there. That decision could still have been appealed to a larger panel of judges at the same court, according to court documents. McAfee had a cell mate at the prison, but that person was not in the cell around the time that McAfee was found dead, a prison official, who asked not to be named, told CNN. The official added the other person was out doing other normal activities at the prison. Asked if authorities had imposed special monitoring measures on McAfee in his cell, the official said, “I’m not aware of that.” McAfee was arrested in Spain in October after being indicted in the United States for tax evasion months earlier. He allegedly failed to file taxes for four years despite earning millions in income between 2014 and 2018 from promoting cryptocurrencies, consulting work, speaking engagements, and selling the rights to his life story for a documentary, according to court documents. The amount he owed was not specified in the indictment. The Spanish judges approved his extradition to face charges for the 2016, 2017 and 2018 tax years. In a virtual hearing in Spanish court earlier this month, McAfee argued that the US tax evasion charges against him were politically motivated, the Associated Press reported. McAfee — founder of the eponymous antivirus software firm, with which he is no longer affiliated — was also indicted in March on separate fraud and money laundering charges. The US Department of Justice alleged that he and a business partner participated in a scheme that earned more than $13 million by falsely promoting cryptocurrencies to unwitting investors. The final two decades of McAfee’s life included a somewhat bizarre series of events. In 2012, McAfee briefly vanished after fleeing his home in Belize because local police tried to question him on the death of his neighbor. (He has denied involvement in the death and claimed he fled because he feared for his life.) He spent time in Guatemala, and then moved to Montreal, Canada, where he worked on a documentary about his life. He ran for US president in 2016 as a Libertarian, and launched a new security product that he called “a f—ing game changer.” Correction: An earlier version of this story gave an incorrect date for the extradition ruling. The three-judge panel made the ruling on Monday, June 21, and lawyers for both sides were notified of it Tuesday, June 22.