A federal judge has tossed out evidence obtained by the Federal Bureau of Investigation FBI for a child pornography case through a hacking operation.

Judge Robert J. Bryan of the U.S. District Court for the Western District of Washington wrote that the evidence obtained should be excluded because the FBI refused to disclose the code used to obtain the evidence, according to a U.S. News and World Report story.

The defense for Jay Michaud, who was arrested in July 2015 on child pornography charges, argued that the FBI should reveal the code used that performed the hack that identified Michaud should be revealed to ensure it did not go beyond what was allowed by the issued warrant. However, the FBI refused to raise the curtain on the code and Bryan said any evidence obtained through the code could not be used in the case.