A pair of doctors who prescribed drugs to Heath Ledger are being investigated by the Drug Enforcement Administration (DEA) in the wake of the actor's Jan. 22 overdose death, MSNBC reported Feb. 28.

"We are investigating doctors in Los Angeles and Texas with regard to Ledger's prescriptions," a DEA source told People magazine.

An autopsy found that Ledger died from a toxic combination of legal prescription drugs. The DEA is focusing on the actor's prescriptions for Oxycontin and Vicodin and whether they were obtained legally.