Journalist Michael Hastings had returned to drugs after 14 years of sobriety and had traces of amphetamine and marijuana in his system when he drove his car into a tree hours after he was seen passed out in his home, according to an autopsy report released Tuesday.

Coroner's investigators said the drugs likely did not contribute to the June crash, which they classified as an accident. But their use by the 33-year-old Hastings, coupled with family accounts to investigators, shed new light on the death of the award-winning journalist whose reporting led to the resignation of a top American general.

The autopsy report came two months after Hastings' death on a deserted Los Angeles street fueled conspiracy theories and prompted the FBI to release an unusual statement that it had not been investigating him.

Investigators said the crash occurred a day after Hastings returned from New York, where his wife was living at the time, and hours before a brother was due to join another family member in urging Hastings to go to detox. Family members told investigators that Hastings had been using the hallucinogenic DMT recently, though the drug was not detected in a blood test after the crash.

The names of family members who spoke to investigators were redacted in the report.

The report said a family member had last seen Hastings passed out at home about three hours before the crash. The person said Hastings had been smoking marijuana the night before the crash.

Investigators said Hastings was found after the crash with a medicinal marijuana identity card in his wallet, and that the drug apparently was used to ease post-traumatic stress disorder after his assignments in Afghanistan and Iraq.

Hastings died instantly of massive blunt force trauma when he apparently lost control of his 2013 silver Mercedes while traveling at high speed and hit a tree in the Hancock Park area of Los Angeles. The crash occurred at about 4:20am and was caught on at least one video camera that showed Hastings driving rapidly through a red light.

Family members told investigators that Hastings had been "sober" for 14 years but started to use drugs again over the past month. He had moved a couple months ago from New York to California and continued his work as a writer for BuzzFeed.

Toxicology results showed small amounts of amphetamine in his blood, which indicated he had possibly taken methamphetamine many hours before his death. Traces of marijuana were also present, indicating he'd taken it hours earlier.

The report also noted that Hastings had hit a pole while driving several years ago and was possibly misusing Ritalin at the time. He was later institutionalized for rehabilitative care.

A family member told investigators Hastings didn't have a history of suicide attempts but believed he was invincible and could jump off a balcony and be fine.

Hastings won a 2010 George Polk Award for his Rolling Stone magazine cover story "The Runaway General," which led to the resignation of US Army General Stanley McChrystal as US commander of coalition forces in Afghanistan.