Billionaire businessman Elon Musk has become a father for the 12th time.

The 52-year-old reportedly welcomed his third child into the world with Neuralink executive Shivon Zilis – with whom he also has two-year-old twins Strider and Azure – earlier this year.

It is not known what sex the baby is, or their name.

“He’s fathered at least 12 children, six of them in the past five years – three with the musician Grimes and three with Neuralink Corp’s director of special projects, Shivon Zilis, including one who hasn’t been known to the public until now,” Bloomberg reported.

“That child was born earlier this year, according to people familiar with the matter, who would only discuss it on condition of anonymity.

“Zilis declined to comment, and Musk didn’t respond to inquiries.”

Musk told Page Six that the new baby was far from a “secret” – adding that issuing a press release would’ve just been “bizarre.”

“As for ‘secretly fathered’, that is also false,” he said.

“All our friends and family know. Failure to issue a press release, which would be bizarre, does not mean ‘secret’.”

That was a happy memory ♥️ The blur on the photo kills my eyes though. Since it’s out there anyway, here is the actual. pic.twitter.com/GxayLT1ECn

— Shivon Zilis (@shivon) September 12, 2023

Musk also has 20-year-old twins and 18-year-old triplets with ex-wife Justine Wilson. They sadly lost their first child due to sudden infant death syndrome at just 10 weeks old.

Musk is also father to X, four, Exa, aka Y, two, and baby Techno, who is known as Tau, with singer Grimes, whose real name is Claire Boucher.

He is also an outspoken advocate of boosting the world’s population.

“The world’s population is accelerating towards collapse, but few seem to notice or care,” he tweeted in 2017, linking an article in New Scientist magazine headlined, “The world in 2076: The population bomb has imploded”.

In 2022, then a father of nine, he claimed claimed declining global birth rates represent “the biggest danger civilisation faces so far”.

-with AAP