(CNN) -- Republican Gov. Terry Branstad of Iowa grew animated during a press conference Thursday discussing a state criminal investigator who claims he was fired for reporting the governor's vehicle speeding.
Larry Hedlund was fired as a special agent in charge with the Iowa Division of Criminal Investigations Wednesday. His termination notice, posted online, states that Hedlund made "negative and disrespectful" comments about the department and its leadership.
A 25-year veteran with the department, Hedlund plans to file a lawsuit for wrongful termination, contending that he was fired not for the comments but for an incident April 26 where he directed a state trooper to pull over a speeding vehicle.
That vehicle was travelling on the highway at more than 80 miles per hour and turned out to contain Branstad and Lt.Gov. Kim Reynolds. A state trooper was driving the car, which was not labeled as a government vehicle.
Branstad defended the termination Thursday. The Department of Public Safety, which oversees the criminal investigations department, "has done what they have a responsibility to do," he said, with cooperation from the state Attorney General's office.
"At no time was there any involvement by me or my office into this investigation," Branstad said.
Branstad, who's up for re-election next year, avoided directly answering questions about whether Public Safety had his full support. He denied Hedlund's contention that the firing had anything to do with the speeding incident.
"There is no correlation, it is absolutely a false accusation," the governor said of Hedlund's claims. "The complaints against him were filed long before this incident."
A statement from the Public Safety department mirrors Branstad's claims: "These allegations are unrelated to the complaint of the April 26, 2013 incident," it says. "Hedlund did not receive discipline as a result of his complaint of the speeding state vehicle."
The termination notice gives no indication of when accusations were first brought against Hedlund. It goes as far back as April 25, the day before the speeding incident, when it mentions Hedlund driving his state vehicle "for no work-related purpose."
When asked when accusations of impropriety were brought, Branstad said he was legally prohibited from disclosing that information by Iowa employment and confidentiality laws. "I would love to tell you everything but the lawyers tell me I can't," Branstad said.
The governor called on Hedlund's lawyer to authorize the full 500-page investigation report to be released to the public in order to prove the firing had nothing to do with the speeding incident. "The public should be able to see all of those facts," Branstad said.
According to Branstad, Hedlund is one of half a dozen Public Safety employees to have been dismissed this year.
Hedlund's attorney, Thomas Duff, said in an interview Thursday that he had not seen the full report but had asked the Attorney General's office for a copy. Duff expected to receive it Monday and said he would release the entire report to the public after reviewing it.
Duff plans on filing the termination lawsuit within the next few weeks, he said. Hedlund's termination notice states that he has never faced discipline before.
According to Duff, Hedlund disputes the charges of disrespectful comments. Moreover, for a clean record of service, "the action of terminating him seems disproportionate to the conduct," Duff said.