A Justice Department lawsuit alleges the illegal prescription-filling by Walgreens included opioids, and began in August 2012.

The U.S. Justice Department is accusing Walgreens of filling millions of prescriptions in the last decade and more without a legitimate purpose, including for dangerous amounts of opioids, according to a lawsuit filed this week.

The U.S. Justice Department on Friday accused pharmacy chain operator Walgreens Boots Alliance of contributing to the U.S. opioid epidemic by filling millions of unlawful prescriptions for addictive painkillers and other drugs.

The Department of Justice sued Walgreens Boots Alliance Inc. for allegedly dispensing opioids and other controlled substances at pharmacies across the US while ignoring red flags that the prescriptions were likely illegal.