An aide at a Long Lake assisted-living center took powerful painkillers from several ailing clients for many weeks before she was caught by Wayzata police officers with two of the pills in her bra, according to investigations by law enforcement and state health officials.

Rebecca V. Swanger, 22, of Delano, now stands charged with felony theft and possession of a controlled substance stemming from accusations that she stole oxycodone, hydromorphone and other narcotics early this year while working at Long Lake Assisted Living.

A state Health Department report released Tuesday said that the onetime aide stole more than 30 prescription pills in all early this year, often replacing them with Claritin and other over-the-counter medication.

The Health Department’s investigator said that Swanger admitted to swapping out the drugs over a two-month period, but she has yet to enter a plea ahead of another court hearing in June. The report placed no blame for the thefts on the center, noting that it had the proper policies and procedures in place at the time.

The case is the latest in a series of painkiller thefts that have alarmed state officials and led to the creation of a task force of health care and law enforcement officials early last year.

The review found 250 cases of prescription drugs being stolen or reported missing at Minnesota health care facilities from 2005 to 2011. The number of reported drug thefts at Minnesota hospitals and nursing homes has more than doubled since 2005, according to the task force, and reflects what experts say is a nationwide surge of prescription-drug abuse, in many cases by health care professionals.

Cynthia Swanger said that her daughter, who is free on bond as her court case proceeds, is contesting the Health Department’s findings.

The mother said the assisted-living center was “looking for a scapegoat” for their own procedural shortcomings, and “they are making Becca the scapegoat.”

The center also overstated the amount of drugs Rebecca Swanger stole, her mother added.

Swanger’s thefts were uncovered when another staff member noticed that the top of one client’s medication cassette did not “pop off” as it should have, indicating that it had been removed and then put back on, the state report read.

That prompted the center’s administrators to set up a sting, said executive director Keith Unger. When pills were found missing, the two aides on duty at that time were immediately confronted by Unger, and Swanger confessed, he said.

She was immediately fired, having worked there for not quite a year, he said.

Swanger was then arrested and questioned by Wayzata police. It was then, according to the state investigation, that officers searched her and found in her bra two pills of hydromorphone, a potent painkiller and a derivative of morphine that brings on a sense of euphoria or bliss.

The clients Swanger stole from were receiving medical care for a range of physical maladies, along with behavioral problems, the Health Department report noted. Unger said none of the clients suffered unduly from the thefts.