Tesla shares tumble after Elon Musk smokes weed on comedian live webcast

Shares in Tesla crashed 6% on Friday as two senior executives quit, just hours after chief executive Elon Musk sparked concern by smoking cannabis on a live web show.

The company's head of accounting, Dave Morton, and head of human resources, Gaby Toledano, said they were quitting the company, which has been at the centre of a string of controversies recently.

Morton, who joined the firm four weeks ago, said he was leaving because "the level of public attention placed on the company, as well as the pace within the company, have exceeded my expectations".

"This caused me to reconsider my future. I want to be clear that I believe strongly in Tesla, its mission and its future prospects, and I have no disagreements with Tesla's leadership or its financial reporting."

Morton joined the company one day before Musk tweeted that he was considering taking the company private with "funding secured". The plan was axed just 17 days later.

Toledano, who has been on leave of absence from the company, said she would not be returning to the company.

The pair quit a day after Musk provoked fresh concern after a joint on a live web show with comedian Joe Rogan.

Taking a puff from a joint – which Rogan said was a blend of tobacco and marijuana and is legal in California – Musk said he "almost never" smoked. "I'm not a regular smoker of weed," Musk said. "I don't actually notice any effect ... I don't find that it is very good for productivity."

Earlier this week Musk escalated his baseless attacks against the British diver Vernon Unsworth, claiming that the man who helped rescue children from a Thailand cave was a "child rapist".