US prosecutors have asked for Megaupload users’ data stored by third parties to be deleted by Thursday, according to a letter from the US Attorney’s Office.

The third party companies referred to were Carpathia Hosting and Cogent Communications Group, according to the prosecutors’ letter.

Megaupload’s lawyer Ira Rothken told a minimum of 50m users could risk losing data, as the letter by US authorities hinted the deletion process could be started by the hosting companies as early as February 2, according to the Associated Press.

The deleted content would also include legitimate and non-copyright-infringing files.

Megaupload was shut down on January 19 on charges of copyright violations, and US authorities have sought extradition of its founder Kim Dotcom (Schmitz) who is undergoing trial in New Zealand.

There have been complaints that users were not able to access legitimate material after the legal action.

If Megaupload wishes to have independent access to the data as it is defending its case, that should be resolved directly with either of the two third parties, according to the letter.

Users who wished to recover their data would have to contact Megaupload, while Rothken pointed out a deal could be reached to prevent users’ data going down and out.