The world's largest movie studios are accusing RealNetworks of destroying and losing key documents in a legal case involving the company's DVD copying software, RealDVD.

In a heavily-redacted legal filing from Wednesday, Sony Pictures, Disney, Paramount Pictures and other large studios allege that RealNetworks "failed to take adequate steps to preserve evidence and, in fact, spoliated evidence." The studios claim that their attempts to address the issue with RealNetworks have been "repeatedly met by stonewalling." And they allege that RealNetworks executives and legal counsel took "active steps to sanitize the discovery record."

In a statement, RealNetworks disputed the claims and said they plan to "contest them vigorously." The studios not only claim that RealNetworks destroyed evidence, but go so far as to allege that RealNetworks executives were involved in the plot.

"...despite repeated requests to Real to explain its actions, there is no evidence that Real took any steps to preserve documents," according to the studios' motion in U.S. District Court in Northern California. The studios are asking a federal judge to impose monetary sanctions on the Seattle software company and order that it preserve all relevant documents moving forward. 

A portion of the motion that is available [PDF, 23 pages] focuses on "engineering notebooks" maintained by Nicole Hamilton, a former senior program manager at RealNetworks who was let go in September.  The studios say that the notebooks were not produced in discovery and RealNetworks doesn't know what happened to them.

"This is shocking given that Ms. Hamilton handed them over to two of Real's executives, whom she identified by name, less than a week before Real filed this lawsuit..." the motion says.

The studios further claim that a lawyer for RealNetworks raised "roadblock after roadblock" in permitting a deposition of Hamilton.

Another issue revolves around an "arccos.zip" file, which the studios say could be highly relevant to the case. The studios claim that RealNetworks first said they did not have the file, later revising the story to say that it was corrupted with a virus, according to the motion. The studios say the archive may contain documents, instructions, manuals and programs showing that RealNetworks' products "are based in part on the work of ... hackers."

Furthermore, the studios say have no way of knowing how many documents were destroyed or the information that they contained.

 "All that can be known is that the documents likely contained highly relevant evidence as they were..." (The rest of the sentence is redacted.) 

According to filings in the case, several documents (including declarations of Rebecca Gose Lynch and John Kelly) have been ordered sealed by Judge Marilyn Patel. A hearing on the matter is slated for March 16 in U.S. District Court in Northern California.

Last month, RealNetworks CEO Rob Glaser said that he expects to win the the RealDVD suit. Movie studios claim that the product  -- which has been barred from distribution by a federal judge -- allows people to illegally copy DVDs to personal computers. 

But in today's statement, RealNetworks said the case is about giving consumers the right to make a back-up copy of DVDs that they have purchased.

"The DVD that you save using RealDVD can only be played back on your computer and it can not be further copied or shared," the company said. "Despite the safeguards we provide in RealDVD, the Hollywood studios want to keep it off the market and control consumers’ fair use rights unfairly. We believe that we have a very strong case, and we are looking forward to our day in court."