Stephany Flores did not view any such information on the laptop after accompanying Van der Sloot to the Lima hotel room where she was killed on May 30, the technology chief of Peru's police, Col. Oscar Gonzales, told The Associated Press.
Van der Sloot's attorney, Maximo Altez, said Gonzales was wrong, but said he had not yet seen the police study of the laptop, which Gonzales said was sent to the trial judge.
Several Peruvian news media reported on the study Thursday without citing sources.
"We deny the colonel's claim," Altez told the AP of Gonzales. "We will be presenting our own expert analysis regarding the laptop." He did not specify what it might show.
Altez says his client plans to plead guilty to killing Flores, but will argue temporary insanity - which is called "violent emotion" in Peruvian law - arguing that he became enraged after she looked in his laptop and learned of his relation to Holloway.
If accepted, that would significantly shorten his sentence as he could plead guilty to manslaughter.
Van der Sloot, 23, is accused of first-degree murder in the killing of Flores, whom he met at a Lima casino.
First-degree murder carries a 15- to 35-year sentence in Peru. Manslaughter could bring three to five years.
The young Dutchman remains the key suspect in the unsolved 2005 disappearance of Holloway, an 18-year-old Alabama student he met in a casino on the Caribbean island of Aruba.
Van der Sloot has several times confessed and then recanted a role in the disappearance of Holloway, who was visiting Aruba on a high school graduation trip with classmates.
Van der Sloot was indicted last June in Alabama on federal wire fraud and extortion charges for allegedly trying to extort $250,000 from Holloway's mother, Beth Twitty, in exchange for information on where she could find her daughter's body.
According to court papers, Van der Sloot received a total of $25,000 a few weeks before Flores' death, money that investigators have said they believed he used to travel to Peru.
Gonzalez said Peruvian police did not examine the hard drive for information related to the Aruba disappearance.
Associated Press writer Carla Salazar contributed to this report.