Elon Musk denied using illegal drugs on Sunday, claiming "not even trace quantities" of drugs or alcohol were found in his body over three years of random drug tests, after a report in the Wall Street Journal detailed how the Tesla CEO and SpaceX founder's drug use worries colleagues in leadership positions at his companies.

KEY FACTS

Musk smoked marijuana on video during a recording session of the "Joe Rogan Experience" podcast in 2018—a move that landed him in hot water with NASA, who demanded assurances SpaceX was a drug-free workplace in order to retain their status as the only government contractor approved to transport astronauts to the International Space Station.

The billionaire has since downplayed the stunt on Rogan's show, claiming he only took "one puff" of marijuana on the podcast and telling biographer Walter Isaacson, "I really don't like doing illegal drugs."

According to Musk, he agreed to undergo random drug testing for three years after his appearance on the podcast—and claimed "not even trace quantities were found of any drugs or alcohol" have been found in his body since.

Alex Spiro, an attorney for Musk, also confirmed to the Wall Street Journal the billionaire has "never failed a test," and said the newspaper's report included "false facts"—but did not disclose what those were.

In the past, Musk has also admitted to taking ketamine—a dissociative drug—to treat depression.