KANSAS CITY, Mo. — A union representing Columbia police officers is suing the city after it refused to release some public records and asked for what the union called “exorbitant” fees to fulfill the request.

The Columbia Police Officers Association filed the lawsuit Thursday. It alleges that the city violated Missouri’s open records law and wants a judge to order it to release all the documents the union is seeking and to provide a “reasonable and lawful” estimate of the costs of producing the documents.

The suit stems from a July request by the union for all emails between Chief Ken Burton and Deputy Chief Jill Schlude written from June 1 to July 22. The lawsuit alleges the city did not meet reply within the legally required three business days and then said it would cost $840 to fulfill the request.

The lawsuit comes after years of contention between the union and city officials over such issues as safety, shift times and low morale, the association’s executive director, Dale Roberts, said Friday.

“We are in almost constant negotiation with the city over terms and conditions of employment,” Roberts said. “With the first request we’re trying to get a look at the command staff and see if we can find a way to reach a middle ground.” Roberts declined to say why the union asked for emails only from June 1 to July 22.

The city contended it would cost that much because Burton, Schlude and records supervisor Lydia Green would have to review the emails to redact information that was not public record. The amount also included a $142.67 “benefits” charge but that charge was later dropped.

The lawsuit contends a records technician or email search feature could easily find any private information in the emails and that Burton and Schlude did not need to extensively review the records.

In September, the union asked for copies of an anonymous survey department employees took to measure morale in the Columbia police department. The city declined to release those records, contending that the private survey could contain information that would identify the employees and thus were not public records. The union argues that the open record law exempts only individually identifiable records, which does not include anonymous surveys.

Roberts said previous surveys conducted by the city and the union found low morale and a “toxic” environment in the police department. City Manager Mike Matthes passed out a three-question survey at shift meetings in August and has told union officials that his survey found police morale was not low and questioning whether the union’s surveys were honest.

“We just don’t believe what the city manager is saying about the survey,” Roberts said. “So we asked to see (his results).”

City spokesman Steven Sapp said officials would not comment Friday because they were still reviewing the lawsuit.

The lawsuit also asks that the city be ordered to pay the union’s attorneys’ fees, court costs and a $5,000 penalty for each violation.