Kim Dotcom has threatened "further action" against the family of a former United States Democratic Party staffer whose murder has been at the centre of a conspiracy theory in recent weeks.
Dotcom made the comments in an open letter published on the International Business Times website on Friday (NZ time).
Seth Rich, 27, was murdered in Washington DC in July 2016, in what police later described as a robbery gone wrong. The conspiracy theory, which has been widely debunked by various media organisations and law enforcement officials, claims he was murdered because he was behind the leak of Democratic Party emails before the US presidential election.
Earlier this week New Zealand-based Dotcom said he had proof Mr Rich was behind the leaks, which intelligence agencies in the US have determined originated in Russia.
Fox News star Sean Hannity promoted Dotcom's claims, promising a "huge announcement" before backing down. Dotcom has not produced any evidence Rich was behind the hack, saying the dead man's family asked him to "be sensitive to their loss in my public comments".
But he seems to have changed his tune after the Rich family spoke out, condemning an apparent attempt to hack Mr Rich's Gmail account and implying Dotcom may have been involved via the file-sharing site he founded, mega.nz.
"We are outraged that certain individuals continue to try to use Seth's name and memory to advance their political and ideological agendas," the family said in a statement to the Washington Post. "We hope people will think twice the next time someone makes an outlandish claim to have discovered new evidence in this case."
Dotcom has denied having any connection to the alleged hacking attempt.
He said in his open letter on Friday he wanted to "formally request that the family and their representatives cease from making such statements about me going forward".
"If these statements do not cease, it will be necessary for me to take further action. It is ironic that the family complain of others potentially making statements that they fear (without actually knowing) will be incorrect and then make incorrect statements about me themselves.
"I have not taken the step of commencing defamation proceedings in relation to the above statements although I would be entitled to do so in New Zealand."
Dotcom says the family might have trouble accepting he has "to play a valuable part in revealing the truth".
He has requested safe passage to and back from the US, where he is wanted on charges relating to mass copyright infringement, so he can deliver his evidence in person.
Dotcom's open letter comes the same day the political party he founded, the Internet Party, announced it will be contesting the 2017 election - without him.