The Drug Enforcement Administration has launched an investigation into how Heath Ledger got the prescription drugs that caused his death.

DEA officials have requested copies of Ledger’s autopsy, as well as the original police report, TMZ.com reports.

“It’s an ongoing investigation by the New York Police Department and, as always, we’re standing by to assist other investigations,” Steve Robertson, a special agent with the DEA, tells Usmagazine.com.

According to the New York Medical Examiner’s autopsy results released Wednesday, Ledger died of an accidental overdose of prescription drugs.

Six types of drugs were found in Ledger’s apartment at the time of his death. They include:

• Oxycodone, a painkiller marketed as OxyContin
• Diazepam and alprazolam, generic names for the anti-anxiety drugs
Valium and Xanax
• Hydrocodone, which is used in a number of painkillers, including Vicodin
• Temazepam and doxylamine, which are sleep aids

“We’re trying to educate that legal drugs – these prescription drugs – can be just as dangerous as more hardcore drugs when misused or abused,” Robertson tells Us. “Sad to say, this is a perfect example of how even the so-called ‘safe drugs’ can cost somebody their life.”

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