A fired Newport Beach police officer sued the city and Police Department on Thursday, alleging that superiors retaliated against him after he testified in a colleague's civil trial.

Former Officer John Hougan's filing with the Orange County Superior Court alleges that he faced three unnecessary internal investigations, was demoted from sergeant to officer, and then was fired after testifying in 2009 on behalf of a sergeant who alleged mistreatment after rumors circulated that he was gay.

Hougan, who is seeking a judgment of more than $25,000, could not be located for comment.

He asserts in his filing that he was called a traitor by his peers, that a superior took him aside and said his words on the stand were not appreciated, and that he found a picture of a bomb taped to his desk.

Prior to testifying, Hougan said he received glowing reviews, as well as awards and commendations.

Two investigations into Hougan's behavior revolved around "out-of-policy" computer use, according to the lawsuit, although specifics were not given. A third investigation had to do with an incident where Hougan allegedly ran over a bird while patrolling the beach.

He was fired in 2011.

In his lawsuit, Hougan alleges high-ranking members of the department acted unethically or violated department policy without repercussion. He accused one of handcuffing and having sex with a subordinate who was either drunk or passed out, and another of impregnating a police informant. He also said a colleague watched pornography at work.

After he was fired, Hougan said in his lawsuit that his wife, Christine, who worked in dispatch for more than 20 years, faced harassment and was fired. She is also reportedly suing the city.

Hougan appealed his termination to the city's Civil Service Board, but recently decided to withdraw his appeal, according to City Attorney Aaron Harp.

Harp said he couldn't speak to the allegations because the city hadn't seen the lawsuit yet, although he said Hougan was never singled out as a result of his testimony in the sergeant's case. The sergeant who sued, Neil Harvey, won a $1.2-million judgment against the city.

Police Department spokeswoman Kathy Lowe deferred comment to the city attorney's office.

Hougan's Los Angeles-based attorneys, Lawrence Lennemann and John Girardi, said they were not prepared to comment as of Friday night.

lauren.williams@latimes.com

Twitter: @lawilliams30