His investigations uncovered many US Government officials who held Megaupload accounts, it said.
"Guess what - we found a large number of Mega accounts from US Government officials including the Department of Justice and the US Senate."
"I hope we will soon have permission to give them and the rest of our users access to their files," Dotcom told the website.
Many people complained of losing legitimate personal files after Megaupload was shut down in January.
Dotcom told TorrentFreak he was negotiating with the US Department of Justice to allow those users to retrieve their lost files.
"Megaupload's legal team is working hard to reunite our users with their data."
US prosecutors allege Dotcom and his associates used Megaupload to carry out a "mega conspiracy".
They face charges of conspiring to commit racketeering, conspiring to commit money-laundering, copyright infringement and aiding and abetting copyright infringement.
A date for the extradition hearing has been set down in August.
- Herald Online staff