Federals still investigate the death of actor Heath Ledger. It is still a mystery for them who gave the two powerful painkillers Oxycontin and Vicodin to Ledger. The mix of the sleeping-pills and the anti-anxiety drugs, even though found in a small quantity in his system, were lethal for the actor.

According to People magazine, a source among the federal agents said: “We’re still trying to find out who gave him the Oxycontin and Vicodin. We’ll search database to see if we can find out and also credit cards records and so forth. Either someone gave it to him or he bought it himself or he got it online.”

At the moment two doctors, one from California and the other one from Houston, Texas were found not to have any connection with the actor’s combination of painkillers. After an in depth investigation by the Drug Enforcement Administration (DEA) by reviewing their records and questioning them, it was find out that their prescription didn’t endanger Ledger’s life.

Heath Ledger, the 28-year-old actor was found dead on January 22^nd in his downtown Manhattan apartment surrounded by bottles of Oxycontin and Vicodin. As a result, ABC News reports that the medical examiner said “We have concluded that the manner of death is accident, resulting from the abuse of prescription medications.”

However, a source told People that Ledger had given away his past habits and that “everyone spoke so highly of him” so it would be surprisingly to find out that the actor had done this on purpose. In addition, the source said that the investigation might last for another month.

Ledger’s father, Kim Ledger said according to ABC that “Heath’s accident serves as a caution to the hidden dangers of combining prescription medication, even at low dosage.”