Tesla shares have plunged this morning after Elon Musk smoked marijuana and drank whiskey while discussing everything from drugs to the possibility we're all living in a simulation, in a rambling two-and-a-half hour podcast appearance which was live-streamed on YouTube.

The 47-year-old billionaire went on the Joe Rogan Experience late on Thursday night and accepted a joint from the host - after a rambling conversation that also took in the dangers of AI and the possibility China is spying on US citizens through their phones.

Hours later, the company's chief accounting officer Dave Morton resigned citing 'public attention' on the company.

Meanwhile, shares plummeted to nine per cent this morning, wiping $4.3 billion off the company's value. By close of trading they had slightly recovered to a 6.3 per cent drop, reducing the company's value by $3.1bn.

It follows weeks of serious turbulence for both Musk and Tesla, after he falsely announced he was taking the company private in a deal with Saudi Arabia and accused a British hero diver of being a paedophile.

The full experience: Tesla founder Elon Musk was seen smoking a joint in Joe Rogan's podcast recording studio, hours before the share price dropped by nine per cent

Friday is also the last day for VP of Communications Sarah O'Brien and HR head Gabrielle Toledano, both of whom have been off work, on leave.

Toledano's departure was announced on Friday, while O'Brien announced her departure two weeks ago.

Tesla shares, down just one percent after Musk's appearance on the Rogan podcast, fell another seven percent in the half hour after the resignation of Chief Accounting Officer Dave Morton, and then to nine per cent, before recovering slightly to down close to seven per cent.

Morton gave notice on Tuesday that he was resigning, according to a filing on Friday.

Dave Morton gave notice on Tuesday that he was resigning, according to a filing on Friday

Today is also the last day for VP of Communications Sarah O'Brien (left) and HR head Gabrielle Toledano (right), both of whom have been off on leave

'Since I joined Tesla on August 6, the level of public attention placed on the company, as well as the pace within the company, have exceeded my expectations,' Morton said in the securities filing.

'As a result, 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.'

Before the news broke of his executives departures, Musk, who has openly admitted to relying on sleeping pill Ambien, told Rogan on Thursday night that Tesla keeps him up at night, adding 'it's very difficult to keep a car company alive.'

Towards the end of the Joe Rogan Experience podcast, the host lit a 'cigar' rolled with both tobacco and marijuana - a drug which is legal in the state of California - and offered it to Musk.

'You probably can't do this because of stockholders, right?,' Rogan asks Musk.

Musk, who earlier joked that mushrooms - both a harmless fungi and an psychedelic drug - are 'delicious', clarified that the drug is legal, and was seen taking a puff on the joint before handing it back.

'I'm not a regular smoker of weed. Almost never,' he told Rogan.

'I don't actually notice any effect. I know a lot of people like weed, and that's fine, however I don't find it's very good for productivity.'

Puffing away: Musk clarified that the drug is legal, and took a puff before handing it back

During the podcast, the pair discussed everything from kindness to artificial intelligence but also Musk's electric car company Tesla

The 2.5 hour long podcast began with Musk and Rogan discussing his dream of solving traffic problems in Los Angeles by building a tunnel underneath the city - a project which he has already embarked on - and artificial intelligence.

Rogan asked Musk if he is 'honestly and legitimately' concerned about AI and the future of robotics, to which Musk replied 'yes, but it's less of a worry than it used to be.'

'It's not necessarily bad, but it's definitely going to be outside of human control,' before speaking of the danger of using AI being used as a weapon and a future where humans will be able to become part-robots: cyborgs.

'You're already a cyborg, and most people don't even realise. That phone [in your hand] is an extension of yourself.'

Upon pouring themselves a generous whiskey, Musk said he had met former President Obama 'for one reason' and that was to warn him about the danger of artificial intelligence.

He also spoke to the host about growing up and realizing at the age of five that he was different.

'I thought I was insane,' Musk said, explaining that he had kept his 'never-ending explosion of ideas' a secret for fear of being 'taken away' by authorities.

The billionaire also joked with Rogen that the reason why he is able to come up with inventions such as Tesla and roof-tiles with built-in solar cells is because he is 'an alien'.

He was also asked if he believes in the possibility of alternate realities and multiverses, to which he replied that 'we are most likely in a simulation, because we exist.'

I think most likely there are many, many simulations. You might as well call them reality, or you could call them multiverse.'

Musk also passed comment on the recent ban on phones from Chinese company Huawei, which applies to anyone working for the US government or a government contractor over fears of spying.

MUSK'S MUSINGS: BILLIONAIRE'S BEST QUOTES FROM THE JOE ROGAN EXPERIENCE PODCAST On why he comes up with innovations and runs his companies: Musk: 'I'm an alien! - Discussing the possibility we are living in an alternate reality and a 'multiverse'. Musk: 'If you assume any rate of improvement at all, then games will be indistinguishable from reality, or civilization will end. One of those two things will occur. 'Therefore, we are most likely in a simulation, because we exist. 'I think most likely, this is just about probability, there are many, many simulations. 'You might as well call them reality, or you could call them multiverse. - On social media: Musk: 'Be nicer to each other. Don't assume someone is mean. It's easy to demonize people.' Musk: 'It's way easier to be mean on social media than it is to be mean in person.' Musk: 'On balance [my Twitter interactions are] more good than bad, but there is definitely some bad'. Musk: '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.' - Rogan: 'What could potentially be holding the company [Tesla] back? Anything you'd change Musk: 'I wish politicians were better at science. That would help a lot. They [politicians] are pretty good at science in China, I have to say.' - On stopping use of Huawei phones because of risk of China spying on US citizens: Musk: 'If you have, like, top secret stuff, you wanna be careful with what hardware you use, but most people don't have top secret stuff. Nobody really cares what porn you watch! Nobody really cares. National spy agencies do not give a rats a** what porn you watch, they do not care. ' - Rogan: 'You know what could help, mushrooms.' Musk: 'They're delicious.' - Rogan: 'What keeps you up at night?' Musk: 'Its quite hard to run companies. Especially car companies. It's quite challenging. Space X is no walk in the park but a car company, it's very difficult to keep a car company alive. 'You know, there is only two car companies in the history of American car companies that haven't gone bankrupt and that's Ford and Tesla. That's it. We barely survived. ' Rogan: 'How close did you get to folding?' Musk: 'Very close. 2008 is not a good time to be a car company, especially an electric car company, that was like stupidity squared. ' - After puffing on the joint given to him by Rogan: Musk: 'I'm getting text messages from friends asking me 'what the hell are you doing smoking weed?'. 'I'm not a regular smoker of weed. Almost never. I don't actually notice any effect. I know a lot of people like weed, and that's fine, however, I don't find it's very good for productivity.' 'It's like a cup of coffee in reverse. I like to get things done. I like to be useful.' - Musk: 'You're already a cyborg, and most people don't even realise. That phone [in your hand] is an extension of yourself.' - Rogan: 'I don't know how you manage your time, it doesn't seem humanly possible?' Musk: I think people don't totally understand what I do with my time, they think I'm like, a business guy, I think even my Wikipedia page says business magnate.' Rogan: What would you call yourself? Musk: 'A business magnet.' - On sustainable energy and the environment Musk: 'We're really playing a crazy game here with the atmosphere and the oceans. We're taking vast amounts of carbon from deep underground and putting this, putting this in the atmosphere, this is crazy. 'We should not do this. It's very dangerous. We should accelerate the transition to sustainable energy. 'I mean the bizarre thing is that obviously we're going to run out of oil in the long term. There's only so much oil we can mine and burn. That's totally logical, we must have a sustainable energy transport and energy infrastructure in the long term. 'So we know that's the end point, we know that. So why run this crazy experiment where we take trillions of tons of carbon from underground and put it in the atmosphere and oceans. This is an insane experiment. It's the dumbest experiment in human history. Why are we doing this, it's crazy.' - On why he isn't building electrical sustainable energy airplanes: Musk: 'Electric cars are important, solar energy is important, stationary storage of energy is important. 'These things are much more important than creating electric supersonic VTOL[vertical take-off and landing planes].' Musk: The trick [with VTOL] is that you have to transition to level flight. The thing you'd use for vertical takeoff and landing is not suitable for high speed flight. 'The interesting thing about an electric plane is that you want to go as high as possible, but you need a certain energy density in the battery pack, because you have to overcome gravitational potential energy. ' Once you've overcome gravitational potential energy and you're at a high altitude, the energy you use in cruise is very low, and then you can recapture a large part of your gravitational potential energy on the way down. So you really don't need any kind of reserve fuel.' - On fossil fuels: Musk: 'It is the dumbest experiment in history' - Musk: 'I really think people should give other people the benefit of the doubt, and assume that they are good until proven otherwise and most people are actually pretty good people. Nobody is perfect.' - On flying cars Musk: 'If you get one of those toy drones and imagine it's 1,000 times heavier - that's not going to make your neighbors happy. 'If you want a flying car, just put wheels on a helicopter.' - On his plans to eliminate traffic jams in Los Angeles Musk: 'I have this, it's sort of a hobby company, called the Boring Company, which started out as a joke. 'And we decided to make it real, and dig a tunnel under LA. And then other people asked us to build tunnels so we said yes in a few cases.' Musk: 'I'm not saying it's going to be successful. It's not, like, asserting it's going to be successful. But so far I've lived in LA for 16 years and the traffic has always been terrible. And so I don't see any other ideas for improving the traffic. 'So in desperation, we are going to build a tunnel, and maybe that tunnel will be successful. And maybe it won't. 'I'm not trying to convince you it's going to work. Or anyone.' - On his new company 'Neuralink' trying to connect human brains straight to a computer. Musk: 'I think we'll have something interesting to announce in a few months.. that's better than anyone thinks is possible.' Musk: 'Best case scenario, we [humans] effectively merge with AI.' Musk: 'How much smarter are you with a phone or computer or without? You're vastly smarter, actually. You can answer any question pretty much instantly. You can remember flawlessly. Your phone can remember videos [and] pictures perfectly. Your phone is already an extension of you. 'You're already a cyborg. Most people don't realize you're already a cyborg. It's just that the data rate.. it's slow, very slow. It's like a tiny straw of information flow between your biological self and your digital self. 'We need to make that tiny straw like a giant river, a huge, high-bandwidth interface.' Advertisement

While he acknowledged that anyone working with 'top secret stuff' ought to be careful with their choice of hardware, he said it was not something 'most people' should worry about.

'Nobody really cares what porn you watch! National spy agencies do not give a rats a** what porn you watch - they do not care. '

Later on, Musk, who recently who recently accused a British diver who helped rescue the 12 Thai boys stuck in a cave of being a paedophile, spoke about kindness.

'Be nicer to each other. Don't assume someone is mean. It's easy to demonize people.'

Earlier this week, Mr Musk suggested in emails to a BuzzFeed journalist that diver Vernon Unsworth was a 'child rapist'.

Musk also claimed, without providing any evidence, that Mr Unsworth had moved to northern Thailand to take 'a child bride who was about 12 years old at the time.'

The Tesla CEO's attacks on Mr Unsworth, whose efforts were considered crucial to the Thai operation, came after the British diver criticized a well-publicized effort by Musk to lend a custom-built mini-submarine to the cave rescue effort.

Mr Musk responded on Twitter with comments strongly implying that the Briton was a pedophile. He then apologised for this, before repeating the claims this week.

During the podcast, Musk was asked what percentage of his interactions with other people on Twitter was a good idea, with Rogan suggesting 'ten per cent'.

Shocking: Musk called Vernon Unsworth a paedophile after the British diver criticized the Tesla CEOs submarine

Musk replied that 'it's on balance more good than bad, but there is definitely some bad'.

He later added: 'It's way easier to be mean on social media than it is to be mean in person.'

Mr Unsworth, from St Albans in Hertfordshire has, through his lawyer, made it clear that he will be suing Musk over his comments.

'Elon Musk´s ongoing campaign of publishing vile and false accusations against Mr. Unsworth is outrageous,' Unsworth's lawyer, L. Lin Wood, said in an email to Reuters.

'Musk has publicly and clearly stated that he `hopes´ to be sued. Let me be equally clear in response - Musk will be sued - not because of his hopes, but because he deserves to be sued,' Wood said.

Musk's renewed attack on Mr Unsworth, his appearance on the show and his top accountant resigning on Friday saw Tesla's stock and bond prices drop even further today.

During the podcast, Musk revealed that the one thing that keeps him up at night is his electrical car company.

'Its quite hard to run companies. Especially car companies. It's quite challenging. Space X is no walk in the park, but it's very difficult to keep a car company alive.

'There is only two car companies in the history of American car companies that haven't gone bankrupt and that's Ford and Tesla. That's it. We barely survived.

Rogan asked him how close Tesla had gotten to 'folding', to which Musk admitted it had been 'very close'.

The $1.8 billion high-yield bond Tesla issued a year ago hit a record low price on Wednesday. It also became more expensive to insure Tesla's bonds against default.

Tesla's stock has lost more than a quarter of its value since August 7, when Musk tweeted that he had secured funding for a previously undisclosed plan to take Tesla private.

Musk on abandoned that plan on August 24, but he faces lawsuits and a U.S. Securities and Exchange Commission investigation into the factual accuracy of his tweet that funding for the deal was 'secured.'

The incident is weighing on investor confidence and has hurt the credibility of Musk, long viewed by Tesla supporters as its most valuable asset.

A lawsuit was filed on Thursday accusing Musk of trying to 'burn' short-sellers through his false tweet that funding had been secured to take Tesla private.

'This appears to be a textbook case of fraud,' Michael Canty of law firm Labaton Sucharow said in a press release.

'We believe Musk attempted to manipulate the price of Tesla securities with false and misleading tweets, in a directed effort to harm short-sellers.'

Labaton Sucharow is asking for class action status to represent anyone who bought or sold Tesla shares between August 7 and August 17.

Musk has described the infamous privatization tweet - including his assurance that funding for going private was secured - as an attempt to be transparent.