A Clackamas County sheriff's sergeant who blew the whistle on the poor performance of a veteran detective has filed a $1.6 million lawsuit alleging that his supervisors created a hostile work environment after he complained.

Sgt. Matt Swanson filed the lawsuit this week in state court and named the Sheriff's Office, Sheriff Craig Roberts and Undersheriff Matt Ellington. He alleges he was subject to retaliation and harassment after trying in 2015 to initiate an internal affairs investigation into Detective Jeff Green.

Roberts said he had not seen the lawsuit and could not comment. Ellington did not immediately respond Friday to a request for comment.

Green pleaded guilty last summer to two misdemeanors for failing to investigate reports of child abuse. He retired in 2015.

Another Sheriff's Office employee, Deputy Joel Manley, also recently warned the agency of his plans to file a lawsuit for harassment and retaliation.

Manley, a longtime deputy who was most recently assigned to the courthouse, has retired. He alleges that he was harassed by coworkers for refusing to participate in an off-color photoshoot at the courthouse last fall.

Manley also alleges that his frequent complaints to department management about the "boys club" atmosphere in the Civil Division fell on deaf ears.

In Swanson's case, he alleges three high-ranking Sheriff's Office supervisors asked him to revise his internal complaint against Green so it "would be less easily tracked."

He claims Capt. James Rhodes and Capt. Jeff Smith, who was then a lieutenant and a former supervisor of Green, worried the complaint would "make them look bad."

Swanson, a patrol sergeant, says in the lawsuit that he saw their request as "unethical and illegal" and refused to change the complaint.

He alleges Smith was angry and called it a disloyal thing to do. He claims Rhodes asked to meet him behind a public works shop while Swanson was on patrol and "attempted to bully and coerce" him into covering up problems with Green and Rhodes' involvement.

Word of Swanson's internal affairs complaint was spread by agency brass "for the specific purpose of putting pressure" on him to withdraw his complaint "and play ball with the command staff to cover-up Det. Green's illegal activities," according to the suit.

Since raising concerns about Green, Swanson says he's been passed over for promotion and received a poor evaluation based on "false information." He claims he was the subject of a "sham" internal affairs investigation that "intentionally damaged" his reputation.

Swanson also alleges that five months after Green retired, a detective assigned to investigate cases Green had ignored was told not to disclose to victims that their complaints hadn't been investigated.

Green was not interviewed regarding Swanson's complaints, Swanson alleges.

Ellington took Green to lunch and a party was held in his honor at the Sheriff's Office when he retired.

-- Noelle Crombie

ncrombie@oregonian.com

503-276-7184

@noellecrombie