Shortly after, he then tweeted directly at Wikileaks writing "Oh no!" with a video of him reacting to audio saying "You've got mail."
And days before on October 27, he wrote that he knew where the deleted emails are and how to get them legally.
"I know where Hillary Clintons deleted emails are and how to get them legally @TGowdySC @seanhannity @realDonaldTrump. 100% true. Retweet," he wrote.
Dotcom, who is wanted in the United States on copyright infringement and money-laundering charges over his file-sharing website Megaupload, then included a step-by-step guide to how to access them.
"Access all emails Clinton sent or received in the last 7 years," he wrote.
"They are all stored in the NSA spy cloud in Utah. Congress or Senate can request the emails from the NSA."
Clinton's missing emails had long been thought to have been be permanently erased and destroyed beyond recovery.
However, newly released FBI notes suggest the emails still exist in several locations, including a Google server, according to the New York Post.
The German entrepreneur, who has a long-standing relationship with Wikileaks and its founder Julian Assange, had said last year that Assange would be Clinton's worst nightmare in 2016 because he 'has access to information.'
That came to be true as Wikileaks, an organization that has obtained classified documents and official government memoranda, has published tens of thousands of emails hacked from Clinton's campaign chairman John Podesta in recent weeks.
The speculation Dotcom has stirred relating to another possible email dump comes amid a high pressure FBI probe of newly discovered Clinton emails.
FBI agents are currently plumbing the 650,000 emails found on a laptop taken from Anthony Weiner, the estranged husband of a close Clinton aide, Huma Abedin.
Thousands of them could be from Clinton's private server.
Feds had seized the laptop belonging to Weiner in September after DailyMail.com exposed his sexting of a 15-year-old girl.
The FBI, which made a copy of the laptop hard drive, is reportedly targeting only email belonging to Abedin, who apparently had shared the laptop with her husband.
Like Clinton, Abedin used other email accounts besides her state.gov account, including a Yahoo account and clintonemail.com, Clinton's private server, the according to reports citing sources close to the investigation.
What will come out of the probe and when is not known, but the impact of the FBI's bombshell discovery of the new trove of Clinton emails is already reverberating in the neck-and-neck race for the White House.
The latest poll on Tuesday showed Republican nominee Donald Trump edging ahead of Clinton for the first time since May and with only seven days until the election.
Trump has seized on the October surprise to put Clinton on the defensive, while Democrats have assailed FBI chief James Comey for breaking with policy and protocol by effectively reopening an investigation into Clinton's handling of state secrets so close to the elections.
