Web users that stored data through file-sharing service Megaupload.com may see their files deleted on Thursday.

According to lawyer Ira Rothkenn who is acting on behalf of the seven men arrested by US authorities last week over the site, data was previously stored by third-parties including Carpathia Hosting and Cogent Communications Group. However, the authorities have frozen Megaupload.com's funds meaning the firms are now not being paid.

Furthermore, in a letter that was filed by the US attorney's office in court last week, the firms were told they could begin deleting the files as the US authorities have copied some but not all of the data.

Megaupload.com was shut down by US authorities for copyright infringement earlier this month after seven employees Limited, including the file-sharing sites' founders; Kim Dotcom, who has previously been known as Kim Schmitz and Kim Tim Jim Vestor, and Mathias Ortmann, were arrested and charged. The US Justice Department claims Megaupload.com has cost copyright holders $500m through illegal file-sharing and had generated $175m in illegal profits.

Megaupload allowed web users to post files to the firm's servers. They would then be given a link to the content, which included music, videos and pornography, could be distributed and allow other web users to access the files. Megaupload did not allow web users to search for content and instead relied on those that uploaded the files sharing the link themselves.

However, the file-sharing site says its more than 150 million registered users who simply stored and shared their own personal files such as family photos.

Rothken revealed the firm is trying to stop the data being deleted, not only for web users but also so the arrested could defend themselves in court.

"We're cautiously optimistic at this point that because the United States, as well as Megaupload, should have a common desire to protect consumers, that this type of agreement will get done," he said.

Carpathia Hosting said in a statement it "does not have, and has never had, access to the content on MegaUpload servers and has no mechanism for returning any content residing on such servers to MegaUpload's customers".

"The reference to the February 2, 2012 date in the Department of Justice letter for the deletion of content is not based on any information provided by Carpathia to the US Government. We would recommend that anyone who believes that they have content on MegaUpload servers contact MegaUpload. Please do not contact Carpathia Hosting."