The 22-year-old is currently in a Lima jail, accused of killing a Peruvian woman.
Van der Sloot's lawsuit claims that the lawyer who represented him during his alleged confession is a private attorney, who pretended to be a public defender.
Under Peruvian law, a suspect who does not hire a private lawyer is provided with a public defender.
A motion by van der Sloot seeking to throw out his confession was dismissed June 25. Van der Sloot recanted the confession in a jailhouse interview with the Dutch newspaper De Telegraaf, claiming it was made under duress.
On the night of June 7, police announced that Van der Sloot had confessed to the murder of Stephany Flores on May 30 in his Lima hotel room. The charge carries a maximum penalty of 15 to 35 years in prison.
Van der Sloot also remains the sole suspect in the unresolved 2005 disappearance of U.S. teen Natalee Holloway on the Caribbean island of Aruba.
AP contributed to this report.