Several police officers in southern Ontario's Niagara region have been caught cheating on exams that are part of the force's promotion process.

This spring, 75 officers wrote tests and went through rounds of interviews, vying for 17 supervisor jobs as sergeants and staff sergeants.

But it turns out someone leaked the tests and questions in advance.

"It's very disappointing yes, and it's very difficult," said Niagara Regional Police Service Chief Wendy Southall.

Southall said an officer came forward in late April to announce someone had tipped off some officers by providing tips and questions for upcoming exams.

The police chief wouldn't say precisely how many officers were involved, but she confirmed between six and eight officers are now facing informal discipline.

"The most important thing I believe in their day-to-day duties, aside from the operational techniques that they know, is honesty and integrity," Southall said. "And do some breach it? Unfortunately they do… it's a very small number."

'Personnel issue'

The officers have not been named, in accordance with the provisions of the Police Services Act, a news release issued by the police force said.

"To date, they have all been complete employment and personnel issues and they will remain anonymous at this point," the police chief said.

The news release said the officers involved have "all accepted disciplinary penalties that include ineligibility to compete in the promotional process."

Beyond that, Southall will not say what punishment the officers will receive.

CBC News has learned the leak came from the human resources department. Southall would not comment on any possible consequences for the people behind the leak.

The force has had to scrap and re-design its promotional testing.

Southall said she doesn't believe previous years' promotional exams were in any way compromised.

The investigation into the allegations is ongoing, Southall said.