

Billionaire Elon Musk took viewers by surprise late Thursday when he smoked marijuana and drank whiskey during a live interview. The Tesla chief executive was speaking with comedian Joe Rogan, an advocate of legalizing weed, on his live internet show when he was handed the joint. A spokesperson for Tesla was not immediately available for comment when contacted by CNBC. "Is that a joint? Or is it a cigar?" Musk asked Rogan before being told it was a cigarette containing marijuana, which is legal in California, and tobacco. Asked whether he had tried it before, the entrepreneur said: "Yeah, I think I tried one once." "You probably can't because of stockholders," Rogan said, to which Musk retorted: "I mean it's legal, right?"

The two had been engaged in a lengthy discussion on a number of issues including humanity, artificial intelligence, Tesla and China. Elsewhere in the podcast, which ran for roughly 2 hours and 30 minutes, Musk is handed a Samurai sword by Rogan, which he observes with keen interest. Musk also brought into the studio one of his tunneling firm's flamethrowers — which sold out mere days after they went on sale at the start of the year. He is seen wielding it in an Instagram post by Rogan.

Rogan's podcast "The Joe Rogan Experience" is one of the most popular in the U.S. Within five hours, his interview live stream with Musk on YouTube had attracted almost 450,000 viewers, and 3.2 million people are subscribed to his YouTube channel.

Musk's Twitter wars

Musk addressed his tweeting habits on the podcast, debating with Rogan whether his direct engagement and battles with people on the platform was a "good idea." "I think it's on balance more good than bad but there's definitely some bad so hopefully the good outweighs the bad," he said. Speaking about how he deals with negative comments directed at him on the social network, the businessman said he mostly ignores them. He said: "The vast number of negative comments, the vast majority of them I just ignore them. Every now and again I get drawn in, it's not good. I make some mistakes." Musk, who founded X.com, a precursor to PayPal, recently got into hot water when he accused a British man involved in the mission to rescue a Thai boys' soccer team trapped in a cave of being a pedophile. The executive called Vernon Unsworth a "pedo guy" on Twitter after the cave diver called his idea to save the trapped boys with a miniature submarine a "PR stunt." Musk subsequently apologized, but has sunk further into the controversy, having made two more attacks on the cave explorer. He most recently called Unsworth a "child rapist." The Briton is preparing a civil complaint for libel against Musk, his attorney said.

Tesla shares fall

The news may be of interest to shareholders, who recently took the company's stock price through a roller-coaster ride in August after Musk said he wanted to take Tesla private — only to then row back on that position.

Musk insisted he was not on weed at the time during an extensive interview with The New York Times. The executive shocked investors when he said he was considering taking the firm off the stock market at $420-a-share — 420 being a popular code term for cannabis. "It seemed like better karma at $420 than at $419," he told the Times. "But I was not on weed, to be clear. Weed is not helpful for productivity. There's a reason for the word 'stoned.' You just sit there like a stone on weed." Traders are concerned the company may still need a capital injection to help with its cash burn problems. Tesla shares were down 1.2 percent Friday in premarket trade.

WATCH: Tesla and Elon Musk's wild August — in nine minutes