The lead auditor in the city of Windsor, Ont., is accusing most members of city council and several top administrators of creating a toxic workplace, which has forced her to leave her job.

CBC News has obtained a letter from Angela Berry, which council discussed in private on Monday. Berry has requested a formal investigation into allegations of workplace harassment and violence.

In her letter, Berry stated she has been absent from work for about a month because of a work-related injury. She claimed it was caused by abuse endured over long-term exposure to an adverse work environment. She mentions "violence, harassment and mobbing."

Berry said the abuse started seven years ago. Her list of alleged abusers include the city's Chief Administrative Officer, the corporate leadership team, audit committee and all of city council - except for Councillor Alan Halberstadt. She said Halberstadt has been a "consistent, clear voice of support."

Berry claimed she reported many concerns over the past three years, but little has been done to remedy the situation.

The mayor and some city councillors describe the allegations as a "surprise" and "without basis." Mayor Eddie Francis said there was no history of Berry's complaints.

"If these conditions did exist, you would expect the lead auditor to take steps to bring them to somebody's attention, and I'm told that is not the case," said Francis. "Throughout the entire process and through all departments and agencies, everyone came back and said this is the first time they've heard of this."

Berry has hired lawyer Peter Hrastovec, who said an internal investigation will be conducted. City council has hired an outside lawyer to handle the investigation.