HALLOWELL — A private investigator will examine a second allegation of sexual misconduct against Police Chief Eric Nason, city officials said Tuesday.

Nason also was investigated by the Maine State Police last year for allegedly sexually assaulting a police officer he still supervises. State police concluded the investigation without filing any charges against Nason.

Hallowell’s investigation was prompted by four-page complaint to Hallowell officials last month by a 43-year-old Rome woman. The woman also sent her complaint to the Kennebec Journal, whose policy is not to identify alleged victims of sexual abuse.

Nason’s attorney, Walter McKee, didn’t respond to messages seeking comment by deadline Tuesday. When reached by cellphone in the evening, Nason declined to comment, saying McKee is handling communication for him.

In the complaint, the woman alleges that while dating Nason for less than two years in the late 1990s, she discovered that he had taken a pornographic picture of her while she slept that showed two other policemen posing in front of her.

City Manager Michael Starn, who is Nason’s supervisor, said the City Council gave him informal approval during an executive session on Monday night to hire a private investigator to look into the woman’s complaint against Nason.

“I see it as a serious complaint,” Starn said. “It was sent in as a serious complaint and we’re going to treat it as a serious complaint.”

In an interview, the complainant said she didn’t initially go to police when she discovered the photo in 1997 because she and Nason attempted to “work through” the issue. But the relationship broke up later, the woman said, because she didn’t trust him.

“He just didn’t want to get caught,” the woman said. “He wanted everything to go away, and I couldn’t live with that.”

The woman says she finally called the state police in 2000 to lodge a complaint, but by then she had destroyed the photo and was told by police that they couldn’t take any action without it.

Starn said the investigation by the private eye probably would cost $4,000 and it will begin shortly, taking a week or so. He would not name the investigator, but Thomas Cumler, of Professional Private Investigations in Manchester confirmed in a telephone interview Tuesday that he has an oral agreement with the city to investigate the complaint.

Cumler, a former Augusta police officer who has been a private eye for 28 years, wouldn’t comment on how he would investigate; but Starn said the investigator would interview people named in the woman’s complaint and report back to the city.

Starn said Nason won’t be placed on administrative leave during the city’s investigation, because he said “doing so before” all facts are found “would kind of, in my view, color the investigation.”

Nason, 48, also was left on the job last year after Starn found out Maine State Police were investigating the chief after he was accused of sexual assault by a female officer, now 22, last June. That case began after an encounter at Nason’s camp in which the officer has maintained she was too intoxicated to consent to sex with the chief. Nason has said through McKee that the two had consensual sex that night. Both have admitted having a sexual relationship prior to the incident.

Mayor Mark Walker has suggested a new city policy to guard against inappropriate workplace relationships between supervisors and staff, in response to the incident. The council on Monday voted to ask a committee to examine city personnel policies.

No charges were filed when last year’s case was closed in October, and the city never commissioned an outside investigation of the department or disciplined anyone because of it.

State police have withheld details of their investigation. The Kennebec Journal is suing the state police in Kennebec County Superior Court for police reports and other case accounts.

Meanwhile, the city says it is trying to get the same police records, which they probably could shield from public view because state law treats most personnel-related records as confidential. The private eye’s probe won’t examine the Hallowell officer’s claims, Starn said.

City councilors are now tight-lipped on the investigation.

Last month, City Attorney Erik Stumpfel drafted a legal memo outlining the council’s role in an investigation. He advised councilors not to disclose any information for fear that it may jeopardize the grievance process, which would be led by council members.

During a closed session with Stumpfel on Monday, officials “agreed that it was appropriate to confirm there was an investigation ordered and started,” Walker said, “but that was it.”