"The handwriting is suspect & I doubt the authenticity of the note," Janice McAfee said in tweeting out a photo of the note. "This note does not sound anything like someone who has no hope and is contemplating ending their life. This note sounds like one of John’s tweets."
The Associated Press first reported that the 75-year-old was found with a suicide note in his pocket, which came as a surprise to Ms McAfee and her lawyers.
An image of the one-page missive written in capital letters, posted with the hashtag #NotASuideNote, purports to show some of Mr McAfee’s final thoughts before he was found dead in a Spanish prison.
"I am a phantom parasite," the note begins, before some words are crossed out.
“I want to control my future, which does not exist,” another part reads.
Ms McAfee previously said the story of his suicide was already prepared and presented to the public before she or his attorneys were notified of his death, and that the "convenient" story was not mentioned when she collected his belongings.
"And if this note was found in his pocket where are the markings of the note being folded into his pocket?" she said in Tuesday’s tweets.
While Spanish authorities are conducting an autopsy, El Pais cited unnamed sources in June saying preliminary results concluded he died by suicide.
McAfee had become increasingly worried before his death he would be “whacked” to keep him silent; warning in 2019 that US officials said they were “coming for” him.
Following the “subtle messages”, he got “$WHACKD” tattoo on his right arm as evidence that he wouldn’t take his own life, saying “If I suicide myself, I didn’t. I was whackd”.
McAfee was found dead in a Barcelona prison cell about a week after he testified to a Spanish court that he feared spending the rest of his life in prison if extradited to the United States.
In 2020, he told followers that if he died in prison, it would not be by suicide, saying “know that if I hang myself, a la Epstein, it will be no fault of mine”.
Ms McAfee suggested in her statement that the "fighter" was not suicidal, saying they spoke twice on the day of his death to discuss the next steps in the legal battle during the months before extradition.
"Besides that John had already won a victory before the hearing in that seven of the 10 charges in the case were dropped in the days leading up to his hearing," she said.
"John was a fighter and he had so much more fight left in him. He told me to be strong and not to worry, we would continue to fight all the necessary appeals."
McAfee was arrested at Barcelona’s international airport in October, with the Spanish court ruling to extradite the billionaire to face a Tennessee arrest warrant.
The state’s prosecutors allege McAfee didn’t report earnings from cryptocurrency and speaking fees, as well as income from selling the documentary film rights to his life story.