“As for ‘secretly fathered,’ that is also false,” Musk told the outlet. “All our friends and family know. Failure to issue a press release, which would be bizarre, does not mean ‘secret.'”

It’s his third child with Zilis. The billionaire quietly had twins with the Neuralink executive in 2021, according to court documents that showed Musk filed a petition to change the twins’ names to “have their father’s last name and contain their mother’s last name as part of their middle name.”

It’s not clear how many children Musk has in total, but he has 11 living who are publicly known: five with his first wife, the author Justine Musk, three with the musician Grimes, and three with Zilis.

Musk cofounded Neuralink and serves as its co-CEO. The company develops brain-computer technology. The news about another child with Zilis comes a couple of weeks after The Wall Street Journal reported Musk had “boundary-blurring relationships” with female employees at SpaceX.

One former SpaceX employee accused Musk of asking her to have his babies on more than one occasion, the report said. The Journal said she declined the offer and later said she was denied a raise. The outlet reported that she eventually left the company and received an exit package valued at over $1 million.

Musk has talked publicly for years about his views on the risks of declining birth rates and has said he considers the issue to be the biggest threat to civilization. He has also said he’s encouraged his friends to have more children. A day after Business Insider reported he had fathered twins with Zilis, he posted on X that he’s doing his best “to help the underpopulation crisis.”

Musk isn’t the only tech mogul who wants to reproduce as a way to save humanity. The ideology has gained traction among some powerful figures who believe they can counteract the risks of falling birth rates by producing genetically superior offspring.

Zilis and Musk did not immediately respond to requests for comment.