In the complaint, the Dutch national, 22, says his June 3 arrest in Chile was executed without a proper warrant. He also claims he was confused during the interrogation because authorities did not provide an official translator, El Comercio reports.
"All this with the intention of pressuring me to accuse me of homicide," he said, according to a document obtained by Peruvian news program 24 Hours.
Van der Sloot recently retracted his confession, telling a Dutch newspaper he was "very scared and confused during the interrogations."
During the prison cell interview, he claims he only admitted to killing Flores, a business student, because police intimidated him and promised he would be transferred back to the Netherlands.
According to police, Flores was murdered on May 30 – five years to the day U.S. teen Natalee Holloway disappeared in Aruba. Van der Sloot was arrested twice but never charged in that case.