An Edmonton woman has been charged with stealing more than 400,000 Percocet tablets from the pharmacy where she worked.

The tablets have an estimated street value of $2 million, Edmonton police said Tuesday in a news release.

Police said they will not release the woman's name to protect the identities of two children who were living in her home.

"The investigation was actually initiated by the Alberta College of Pharmacists," said Cheryl Voordenhout, spokesperson for the Edmonton Police Service.

"They noticed a discrepancy in the amount to Percocet being ordered, versus the amount being distributed, and notified police."

The police investigation found that a total of 401,500 Percocet tablets were stolen from a pharmacy the woman worked at in the Beverly neighbourhood between January 2017 and April 2018.

That amounts to an average of more than 26,000 stolen pills each month.

Percocet is a combined opioid/non-opioid pain reliever.

Several other types of medications were also discovered missing from the pharmacy.

"The employee, essentially, was ordering medication under the names of pharmacy patrons, and then the drugs were not being distributed," Voordenhout said.

During a search warrant executed at the woman's home on April 26, 2018, police recovered a stolen firearm. Two children were present in the home.

The 34-year-old woman was arrested on July 26, 2018, and has been charged with 11 offences:

theft over $5,000;

possession of stolen property over $5,000;

possession for purposes of trafficking;

fraud over $5,000;

false pretence over $5,000;

identity fraud with intent to obtain property;

unsafe storage of a firearm;

possession of a restricted firearm;

possession of a loaded firearm;

two counts of causing a child to be in need of intervention.

The two children are now back in the home, Voordenhout said.

The woman charged by police was not a pharmacist or a pharmacy technician but simply an employee, the Alberta College of Pharmacy said in a statement Tuesday.

The college said it is investigating "potential contributing factors" at the pharmacy that could have prevented, or contributed, to the theft of such a large amount of Percocet.

"The loss of this quantity of prescription drugs, and particularly a drug that is subject to abuse, is of great concern to our college," the statement said.

The accused is scheduled to make her first court appearance Sept. 12.