A fired criminal investigator filed a lawsuit Thursday accusing top Iowa Department of Public Safety officials of retaliating against him for complaining about Gov. Terry Branstad's speeding vehicle and other departmental misconduct.

Larry Hedlund, former special agent in charge with the Division of Criminal Investigation, filed the lawsuit in Polk County alleging that his firing last month was in violation of public policy and unfairly destroyed his 25-year career. His lawsuit names DPS Commissioner Brian London, DCI Director Chari Paulson and Assistant DCI Director Gerard Meyers.

It seeks damages for lost wages and benefits and emotional distress. The lawsuit does not name Branstad, who appointed London last year to lead the department, which includes DCI and the Iowa State Patrol.

Hedlund also filed for an injunction that could thwart a review by former Iowa Chief Justice Louis Lavorato, who was appointed by Branstad last month to investigate Hedlund's firing and claims of retaliation. The request for injunction contends that state officials illegally shared a confidential 500-page internal affairs report on Hedlund's firing with Lavorato in violation of the state's public records law and seeks the return of the document and a fine. Hedlund contends the report is defamatory and inaccurate.

Hedlund and his attorney, Tom Duff, plan a news conference in Des Moines to discuss the lawsuit Thursday afternoon.

Branstad has denied retaliation and defended Hedlund's firing as a justified action against a disruptive employee, but the speeding incident and related fallout have dogged the governor for weeks.

Hedlund sought to have Branstad's vehicle pulled over April 26, when a black SUV zipped past him traveling "a hard 90" mph on a state highway near Fort Dodge. After Hedlund called a dispatcher to report the vehicle, a deputy clocked it traveling 84 mph. Trooper Matthew Eimers raced to catch up, but let the vehicle go after learning it was fellow trooper Steve Lawrence transporting Branstad and Lt. Gov. Kim Reynolds in "Car 1," the governor's state-assigned Chevy Tahoe.

Hedlund filed a complaint to Paulson and London on April 29, saying the pursuit of the governor's vehicle endangered public safety and had to be addressed. He alleged the speeding was a common practice done at the behest of the governor and vowed to pursue an investigation as the senior law enforcement official involved. Paulson responded by asking Hedlund why he was driving a state vehicle on a scheduled vacation day.

Two days later, Hedlund was removed from duty and placed on paid administrative leave. The lawsuit alleges that Meyers told him that day: "This isn't the way it is supposed to be done, but this is what the commissioner said to do."

After a 2 1/2 month review by the department's Professional Standards Bureau, Hedlund was fired July 16 for writing disrespectful and negative emails about Paulson's leadership of DCI, including criticism of a plan to require agents to type their own reports, and other unbecoming conduct.

Hedlund, who was based in Fort Dodge and supervised agents in northern Iowa, had no prior discipline. He had won a federal award in 2008 for his role in helping a domestic abuse victim.

Lawrence received a $181 speeding ticket and unspecified discipline from the department last month. Branstad has ordered that troopers assigned to his security detail follow all traffic laws, except during emergencies. He's also requested a review into the use of 3,218 undercover license plates for government vehicles, including his own, that are kept out of law enforcement databases, allowing them to avoid tickets from traffic cameras.