RALEIGH, N.C. — Raleigh's police chief said Tuesday that the department is aggressively tackling alleged double-dipping and that the investigation is being conducted comprehensively and on every level of the department.

"The investigation is being conducted in a manner that seeks the truth and will ensure fairness for all involved," Chief Jane Perlov said during a 15-minute news conference at the Raleigh Police Department.

She also said that the public should have confidence in the fact that the department is policing itself but that it should also understand that police officers are not immune to making mistakes.

Still, Perlov said, "Police officers must be held, and more importantly, must hold themselves to the highest standards of accountability and honor."

Perlov offered little new information about at least five police officers under investigation for allegedly working off-duty jobs while they were supposed to be working for the city.

The allegations surfaced, she said, as the result of a routine audit in May that uncovered irregularities in off-duty employment records. After the issues were brought to her attention, Perlov said that she referred the items in question to the department's internal affairs unit.

For Raleigh police to work two jobs is not uncommon and is legal. Perlov said Tuesday that about 602 of the department's 730 sworn officers are authorized to do so.

A city ordinance even requires that certain businesses use uniformed security, and most of those businesses use off-duty police officers. Officers set their own work schedules, but the police department must approve the jobs.

Perlov, however, said there were three other possible violations of the off-duty employment guidelines: officers working more than the allowed 14 off-duty hours per week, officers working while on sick leave and officers not getting approval for their second job.

"Cases that may involve statutory violations will be referred to the Wake County District Attorney's Office for a review," Perlov said. "Based on what we have learned to date, those referrals will likely involve a very few officers."

John Midgette with the Police Benevolent Association, which represents about 500 police officers in the state, said that as many as nine of its members have sought advice about the investigation and that the group supports the internal investigation based on the facts.

"We fully support a proper and thorough investigation," Midgette said. "We just ask that there is full procedural due process and the facts become the center of the process rather than speculation and conjecture."

On Friday, Perlov said, she sent a memo out to all police department employees, reminding them of the rules regarding off-duty employment and asking them to adhere strictly to regulations.

Possible disciplinary action against officers found to have violated the rules runs from a verbal reprimand to termination of employment, Perlov said. She would not say whether any officers have been reassigned or put on desk duty during the investigation.