The U.S. Justice Department has filed a lawsuit accusing Walgreens of filling millions of prescriptions for Americans over the last decade and more without a legitimate purpose, including for dangerous amounts of opioids.

If found liable, Walgreens, which is one of the country's largest pharmacy chains with over 8,000 pharmacies across the U.S., could face civil penalties of up to $80,850 for each unlawful prescription, the Justice Department said in a statement.

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.

The U.S. Department of Justice has filed a lawsuit against Walgreens Boots Alliance (NASDAQ:WBA) in Illinois federal court for dispensing millions of unlawful prescriptions over a 12-year period, driving Walgreens (NASDAQ:WBA) shares sharply lower in after-hours trading.