KNOXVILLE (AP) — A lawsuit by Tennessee Attorney General Herbert Slatery says Endo Pharmaceuticals sales representatives for years ignored warning signs of drug dealing at pill mills across the state.

The Knoxville News Sentinel reports Slatery says suspicious pharmacists began refusing to fill prescriptions and Endo sales reps stepped in to find willing pharmacies. The lawsuit made public this month says Endo tracked sales in real time and knew their so-called "abuse-resistant" opioid was popular with addicts.

Slatery says company executives blamed the sales strategy on a system that graded doctors on prescription numbers. One A-grade doctor prescribed an estimated 604,000 pills over seven years. He was jailed last year for health care fraud. Nearly 170 other doctors have been awarded the same grade. The company has yet to file a legal response.