Gearbox Software has filed a lawsuit against developers 3D Realms and Interceptor Entertainment claiming the two companies pursued illegal usage of the Duke Nukem IP, violating copyrights held by Gearbox.

News comes just weeks after Interceptor and 3D Realms – Duke Nukem's original co-creators – teased an announcement for Mass Destruction, what appeared to be a new installment in the Duke Nukem series that was allegedly set to be publicly unveiled February 25 via a teaser site. Among the exhibits in the Gearbox's case against the two developers is a document explicitly stating that 3D Realms was at the time of their agreement with Gearbox, blatantly aware of their stripped rights to the property following the Duke Nukem Forever developer's acquisition.

"There is simply no legal basis for what 3DR is trying to do," the document states.

In addition to the breach is a signed declaration from 3D Realms CEO Scott Miller and Duke co-creator George Broussard, admitting the two parties culpability over copyright violation and legal terms with Gearbox.

"Apparently, after selling its Duke Nukem IP rights to Gearbox in 2010, 3DR sought to privately convince others that the sale never happened. Theresult is the unauthorized development effort that reportedly exists between 3DR and Interceptor," Gearbox's complaint reads, raising the question of just what 3DR and Interceptor initially had planned.

[Via Joystiq]