"I have nothing to do with Whaledump or Rawshark," he told RadioLive today.
He hit out at Slater for taking media organisations to court to attempt to stop them from publishing material material from Rawshark and Whaledump.
"Cameron Slater is releasing private information of people that he is targeting in his smear campaigns - and I was personally a victim of that," Dotcom said.
"He has released a private family holiday video that he has purchased from a video editor that was formally employed by me and has released that on his website.
Dotcom said Rawshark had done the country a "great service".
"What we know now is that National is behind smearing of their opponents, they are breaking the law doing it, they are using the unethical methods to get rid of their opponents and the fact that this has been disclosed, I think it a great service to New Zealanders because they are about to vote for their next government."
After earlier announcing he would be revealing information on September 15 that he said would be damaging to the National Party, the internet mogul told RadioLive he believed a large number of undecided voters would wait until that date before casting their votes.
"I urge you, if you know John Key is not your guy, go and vote early."
Polling day is September 20 but booths are open for early voting.
