An Illinois appeals court on Friday vacated an injunction obtained by the Chicago police union that barred the city's release of disciplinary files dating back decades.

The Fraternal Order of Police sued to block the release after a March 2014 appellate court ruling that documents dating back to 1967 should be made public. Several news outlets had requested the records.

As a result of the 2014 ruling, the Invisible Institute, a nonprofit journalism organization, obtained 11 years of records and published an interactive database of police misconduct.

Last year, Cook County Circuit Judge Peter Flynn issued an injunction based a clause in the union's bargaining contract requiring the destruction of public records after four years. The union also claimed releasing the documents would unfairly harm the officers named in the citizen complaints.

The union contends police officers are susceptible to false complaints, and reports that go unsubstantiated should not have an indefinite shelf life. The city of Chicago appealed the injunction.

In its ruling Friday, the appeals court confirmed the records must be released under Freedom of Information Act laws. The court also ruled the union contract clause requiring the destruction of disciplinary records after four years was "legally unenforceable" because it conflicted with the state's public records law.

FOP President Dean Angelo Sr. declined to comment on the ruling, saying he had not yet read it.