A former investigator for the soon-to-be-abolished Independent Police Review Authority was accused Wednesday of leaking a confidential IPRA memo about the agency’s investigation of a high-ranking Chicago Police official, who sources identified as Glenn Evans.

The explosive information about a much-maligned agency accused by the U.S. Justice Department of failing to adequately investigate police misconduct and covering for wayward officers is contained in Inspector General Joe Ferguson’s quarterly report.

The report does not identify the police official under investigation. But City Hall sources identified the target of the investigation as Lt. Glenn Evans.

Ferguson’s report could bolster Evans’ case in a lawsuit against the city that makes similar claims.

The report states that an IG investigation had “established” that a former IPRA investigator “emailed, without authorization, a confidential IPRA memorandum regarding an investigation of a high-ranking Chicago Police Department employee to an individual who did not work for the city and had no connection to the confidential investigation.”

The same investigator also “improperly emailed a confidential lab report regarding DNA testing” tied to that same investigation “from the employee’s official IPRA email account to a personal, unsecured email account.”

Ferguson tried to determine whether the IPRA investigator or co-workers had “leaked” the DNA testing report to a news reporter who had “both publicly reported on and posted a PDF of the confidential report.”

But. the investigator “left the agency and moved out of the surrounding area — beyond the reach of an OIG subpoena.” The reporter declined to cooperate with the IG investigation, the report states.

As a result, Ferguson said his office “could not develop sufficient evidence directly linking the former IPRA investigator or any other city employee to the public reporting and publishing of the confidential DNA report.”

Nevertheless, the IG concluded that the IPRA investigator’s “improper handling of confidential investigative documents violated IPRA’s confidentiality policies and the city’s personnel rules.”

Last year, Evans filed a lawsuit against the city and a dozen current or former IPRA employees.

In it, Evans claimed that a bitter former colleague at IPRA and political pressure to look tough on “dirty” cops led to his indictment for official misconduct and aggravated battery.

The 30-year Chicago police veteran was acquitted in December 2015 after being charged with shoving a gun down a man’s throat. He has escaped suspension in the case of a woman who claims he fractured her eye socket after an arrest.

“IPRA has once again failed the citizens of the City of Chicago by not playing it down the middle with its investigations,” Evans said on the day the lawsuit was filed.

“Shooting victims and police alike deserve a fair and honest investigation.”

Specifically, Evans claimed that Matrice Campbell — one of the 12 current or former IPRA employees listed as defendants in the suit — “has harbored animosity” toward him since Evans filed an insubordination complaint leading to her suspension in 1999, while they were working at CPD’s Second District.

While working at IPRA, Campbell then leaked documents from the Evans investigation to a WBEZ reporter “in order to harm Evans,” the suit claimed. The public radio station and its reporter also were named defendants.

The ensuing media scrutiny and fallout from the release of the Laquan McDonald shooting video created “political pressures” for then-Cook County State’s Attorney Anita Alvarez to press charges, Evans claims.

One month before the lawsuit was filed, IPRA acknowledged that firing Evans over a separate allegation of excessive force was no longer an option because the state’s five-year statute of limitations had expired.

In that 2011 case, Evans allegedly grabbed a woman and pushed her nose after she refused to be fingerprinted after an arrest for domestic disturbance.

The woman, Rita King, claimed he left her with a fractured eye socket, according to a lawsuit she filed against Evans.

IPRA originally recommended a 15-day suspension for Evans in the King case.

After Eddie Johnson became police superintendent, he decided to double the suspension to 30 days. Then IPRA changed its recommendation, saying Evans should be fired for the King incident.

Evans doesn’t dispute that he made contact with King, but he says he grabbed her head because she was spitting in his face. He described his contact with her as a “firm grasp” not a “forcible strike” and said it lasted “mere seconds,” according to court records filed in connection with the suit.

Evans presented a medical expert who ruled out a link between King’s facial injury and the incident.

King claims Evans repeatedly told her “I’m going to push your nose through your brains.”