McAfee, 67, went into hiding after his American neighbour Gregory Faull was fatally shot in November. He made his way secretly to neighbouring Guatemala, but the authorities there deported him to Miami on Wednesday.
"I will not go back to Belize. I had nothing to do with the murder," a relaxed-looking McAfee said in an interview on CNBC.
Police in Belize want to question McAfee as a "person of interest" in Faull's killing, though authorities there say he is not a prime suspect. McAfee said he barely knew Faull and had "absolutely nothing" to do with his death.
Belize police say their country's extradition treaty with the United States extends only to suspected criminals, a designation that does not apply to McAfee.
McAfee, an eccentric tech pioneer, made a fortune from the anti-virus software bearing his name and had lived in Belize for four years.
He has charged that authorities have persecuted him because he refused to pay $2 million in bribes, and that the extortion attempt occurred after armed soldiers shot one of his dogs, smashed up his property and falsely accused him of running a methamphetamine laboratory.
Belize's prime minister has rejected the allegations, calling McAfee paranoid and "bonkers."