Police are investigating a "significant accounting irregularity" at three Nova Scotia health districts.

The Annapolis Valley, South Shore and South West health authorities, which share financial services, said Monday they recently detected a problem and contacted Kentville police.

An employee with Annapolis Valley Health was "dismissed for cause" following an internal investigation, the districts said in a joint news release.

They said a police investigation is ongoing and criminal charges are possible.

Annapolis Valley Health CEO Janet Knox described the employee in question as a junior front-line worker.

"We have done our own internal investigation," she said. "When we determined that there was an irregularity, we immediately did our own investigation and learned enough to say we needed to bring in others."

She said the problem was detected on Sept. 30 and reported to police. Knox would not say how much money is missing.

"We think it probably will be a large amount," she said.

No comment on impact

The districts wouldn't say whether money was missing or moved around, or what impact there might be on their multimillion-dollar operations.

Kentville police confirmed they received a complaint a few weeks ago and were investigating. Insp. Kenneth Reade said search warrants have been executed.

"Once we gather the information from the search warrants, we should be able to determine whether or not there is a misappropriation, a mismanagement or a theft or fraud," he told CBC News on Monday.

A spokesperson with the Department of Health said it was looking at whether the money could be recovered through the courts or through insurance.

The three health districts have a combined budget of more than $200 million.