Elon Musk's bizarre message about aliens building the pyramids of Giza has prompted a response from the Egyptian goverment - and Helen Clark.
After the billionaire shared on Twitter an old conspiracy theory that the pyramids were built by extraterrestrials, a top Egyptian official invited the SpaceX and Tesla founder to come and see one of the "seven wonders of the ancient world" for himself.
On Friday Musk tweeted: "Aliens built the pyramids obv."
He followed up the message by saying: "The Great Pyramid was the tallest structure made by humans for 3800 years."
In response, Egypt's Minister of International Cooperation, Rania al-Mashat, got in touch with the South African-born billionaire.
"I follow your work with a lot of admiration," wrote al-Mashat via Twitter.
"I invite you & Space X to explore the writings about how the pyramids were built and also to check out the tombs of the pyramid builders. Mr. Musk, we are waiting for you," she added.
Egyptian archaeologist Zahi Hawass also responded in a video posted on social media, saying Musk's argument was a "complete hallucination".
"I found the tombs of the pyramids builders that tell everyone that the builders of the pyramids are Egyptians and they were not slaves," EgyptToday quotes him as saying.
Musk's tweet even prompted Helen Clark to add her thoughts. The former PM tweeted: "Even if Elon Musk's statement that Egypt's pyramids were built by aliens was meant as a joke, it isn't funny.
"Egyptians are rightly proud of their extraordinary heritage," she added.
Meanwhile, Musk had more important things to focus on after today's successful test flight and splashdown of the SpaceX crew in the first commercially built and operated spacecraft to carry people to and from orbit.