The parents of Lauren Spierer filed the request for a protective order in U.S. District Court in Indianapolis. The 20-year-old Greenburgh, N.Y., native disappeared in June 2011 after a night of partying with friends in Bloomington.
The motion asks Judge Tanya Walton Pratt to issue an order "preventing public dissemination of sensitive and private information" that may be filed in court during their lawsuit against Corey Rossman and Jason Rosenbaum.
The Spierers' attorneys say releasing that information publicly could interfere with the investigation into Lauren Spierer's disappearance and impede the seating of an impartial jury.
The request filed Wednesday also asks that all material deemed confidential be destroyed within 30 days of the end of the case, The Indianapolis Star reports (http://indy.st/LsSafn ).
The lawsuit filed last year by Robert and Mary Charlene Spierer claims Rossman and Rosenbaum gave Lauren Spierer alcohol and failed to make sure she made it back to her Bloomington apartment safely, leading to her presumed death.
The Spierers have long maintained that the men haven't fully cooperated with investigators. They hope the lawsuit will force the men to answer questions under oath.
Lawyers for Rossman and Rosenbaum had no comment when contacted Thursday by The Associated Press. The attorneys have maintained the Spierers have no evidence their daughter is dead and that their clients weren't responsible for the safety of an adult. Rossman has asked Pratt to dismiss the lawsuit.
No criminal charges have been filed in the disappearance.