Lisa Wilkinson takes on conspiracy theorist David Icke on his theory the moon is a "hollowed out spacecraft." Courtesy: Today Show

JOURNALIST-turned-conspiracy theorist David Icke made an appearance on The Today Show this morning, clashing with Karl and Lisa throughout the interview.

The British former footballer broadcaster - who believes that the planet is secretly ruled by a race of shapeshifting reptiles who control human behaviour - is in the country for a series of talks, charging upwards of $100 for tickets to hear him speak.

As Karl and Lisa tried to wrap their heads around his theories, Icke became increasingly frustrated.

The interview started on the back foot as the hosts introduced Icke by outlining his theories:

“Would you pay more than $100 to sit for 12 hours and listen to a man who claims the world is run by lizard aliens? That’s not all. David Icke is telling the audience on his Aussie tour he believes the moon is a gigantic spacecraft and 9/11 was a conspiracy theory. Good morning to you David.”

We spoke to a man who claims the moon is a hollowed-out space station and things got a little heated... #9Today https://t.co/NXSqKnSfA1 — The Today Show (@TheTodayShow) July 13, 2016

“You know why they are doing it, they have a mind of their own and taken the self-respect to look at the detail and then think that makes some sense, I’m going to know more. That’s why. They are intelligent people,” Icke said.

“I talk for 12 hours and I will swap what I earn with what you earn any day of the week, OK?”

Wilkinson asked Icke to explain some of his unusual views on extraterrestrial life.

“Let’s drill down into some of your beliefs. You think our moon is a hollowed out space station. That’s a hard one to buy, that one,” she offered.

Icke insisted that “mainstream science cannot explain why a body that big, bigger than Pluto, can be going around a planet this small. It makes no sense. They can’t explain how it came into being. Lots and lots of ancient tribes and tribal peoples have the same legend that the moon was brought here and there was a time when the Earth did not have a moon.”

“Shipped in by trucks or something?” Wilkinson asked.

“That’s a good one. Nice one,” said Icke.

Then followed an increasingly fraught back-and-forth about how exactly the moon was “moved” to its current position, before an exasperated Icke told the hosts: “You don’t know what my theories are. You have been briefed this morning by a researcher. You DON’T know what my theories are.”

“I’m trying to understand it on behalf of the audience so they can understand it,” Wilkinson countered, still trying to keep the interview on track.

At this point, Stefanovic decided to focus his energies on a more fruitful pursuit: making “this guy’s loco” faces directly into the camera.

As Icke insisted that “what was in my books in the 1990s is now being read on the television news,” Karl piped up with the real mic drop moment of the interview:

“Look, I love these theories but I’m not slugging people $100 to listen to my rubbish, do you know what I mean?”

“Yeah. That was brilliant mate, well done,” said Icke.

Wilkinson tried another tack, asking Icke about his belief that world leaders are reptilian aliens.

“OK, can you tell us who are the aliens? Is Vladimir Putin an alien?” she asked.

“This is a joke. It’s an absolute joke. You have never read a book, you won’t come and see the talk,” Icke replied.

“You shouldn’t be getting angry. Why are you getting angry?” the hosts asked.

“I’ll tell you why: because it is so serious.”

"People want to pay money unfortunately, because they want to see a train wreck." @RachelCorbett #9Today https://t.co/R3IqXWVG8D — The Today Show (@TheTodayShow) July 13, 2016

With that, they were out of time, but Icke certainly left his mark on this morning’s episode.

Returning from the break, the hosts couldn’t help but make fun of what was a thoroughly watchable trainwreck.

“He was a lovely guy, that last guy,” said sports reporter Tim Gilbert. “He was one of the biggest knobs I’ve ever seen on TV.”

“You know what you are? You’re a reptilian humanoid,” joked Karl.

Later in the show, Wilkinson confirmed that Icke was less than pleased with how the interview had gone.

“Let’s just say he walked out of here not a happy camper. I said, ‘David, you’ll sell a lot of tickets off that,’ and he... well, I won’t repeat what he said.”