(Photo: AP)

(Bloomberg) –Walmart illegally mishandled opioid painkillers sold through its in-store pharmacies for years, two pension funds contend in lawsuits seeking access to internal records of the world's second-largest retailer.

Media reports and information revealed in a mass of opioid lawsuits in federal court show how Walmart failed to comply with laws mandating monitoring of sales of the highly addictive painkillers, attorneys for the Norfolk County Retirement System and the Police and Fire Retirement System of Detroit said in their suits.

Lawyers for states, cities and counties suing the chain to recoup billions of dollars spent dealing with the fallout from the U.S. opioid epidemic contend Walmart "failed to implement basic compliance controls to protect its pharmacies and drug distribution business from being used as cover for the illegal dissemination of opioids," according to the complaints, filed June 16 in Delaware Chancery Court.