A private investigator who called police and reported that he suspected Jim Righeimer of drunk driving denied allegations that he was hired to investigate the Costa Mesa councilman.

Chris Lanzillo, 42, said in a statement that he was on another assignment Wednesday night when he spotted Righeimer getting into his SUV outside of Skosh Monahan's on Newport Boulevard.

"If I was setting him up merely by calling 911, what was the purpose?" Lanzillo wrote Monday night. "Ultimately, an officer would have to make the call on if he violated any laws."

Righeimer, however, contended in a press conference Tuesday that he believes he was targeted by Lanzillo, a Menifee P.I. with ties to an Upland law firm that represents public employee unions, because of his conservative politics. Lanzillo, a former Riverside police detective, served as president of his police association before leaving the department in 2010.

"So what he's saying is he's monitoring City Councilman Gary Monahan's restaurant?" Righeimer said. "It's all the same. It's a chilling effect on elected officials to vote the way that the labor unions want them to vote, which is completely against the best interest of the city itself."

Lanzillo said he could not reveal what he was investigating in Costa Mesa, saying only that it had nothing to do with Righeimer. He said the councilman's assertion of a union setup "does not make sense."

Lanzillo questioned the field sobriety test given to Righeimer, terming it "suspicious." He asked why a Breathalyzer wasn't used. The officer at the scene found Righeimer, who had been drinking Diet Coke, to be sober.

"I believe the officer realized who the person was and thought it was best to leave it alone," Lanzillo said. "This is apparent by [Righeimer's] ... behavior that night and the bully he has become days after the incident."

After placing the call, Lanzillo said he felt "harassed" by police.

"I have never heard of a police lieutenant calling a person the next day to inquire about a call made on a suspected hazardous driver," Lanzillo said. "The California Highway Patrol would never call a person the next day to ask about where I worked and what was I doing. The Highway Patrol has signs all over the freeway asking the public to call 911 on all hazardous drivers."

He said if he were trying to skirt accountability he would not have provided his name and phone number to the dispatcher.

Councilman Steve Mensinger said he believed Righeimer was targeted because of the remarks he made during last week's council meeting about the Lackie, Dammeier & McGill law firm, which has used Lanzillo's services as an investigator.

The firm until Friday provided counsel to the Costa Mesa Police Assn., which said in a statement it was not involved in the 911 call made by Lanzillo. The firm has also said it did not retain Lanzillo to follow Righeimer.

The investigation into whether Lanzillo made a false report to police is ongoing, said CMPD Lt. Tim Schennum.

— Staff Writer Joseph Serna contributed to this report.

lauren.williams@latimes.com

Twitter: @lawilliams30