Elon Musk's father reveals he has second child with his stepdaughter

Elon Musk's father has revealed he has a "secret" second child with his 35-year-old stepdaughter.

Errol Musk, 76, who is an engineer in South Africa, had a child, Elliot Rush, now 5, with Jana Bezuidenhout in 2017.

Bezuidenhout is the daughter of Heide Bezuidenhuot, Errol's second wife.

Jana pictured with her child. Photo / via Facebook

Jana was 4 when Errol became her stepfather. Errol and Heide were married for 18 years and had two children together.

Errol married Heide after separating from Maye Musk, Elon Musk's mother, in 1979.

The senior Musk told The Sun that a second baby born in 2019 was unplanned.

When asked by The Sun what Jana's stepsisters thought about the relationship, Errol said they found it "creepy".

"They still don't like it. They still feel a bit creepy about it, because she's their sister. Their half-sister," Errol told the Sun.

Errol's former wife Heide is seen holding baby Elliot Rush, with Jana left and daughter Asha, right. Photo / via Facebook

Errol now has a total of seven children, including Tesla CEO Elon Musk.

Meanwhile, last month it was revealed Elon, the billionaire Tesla founder, had twins in November with Shivon Zilis, a director at one of his companies.

Musk has a known total of nine children. He also has two children with Claire Boucher, better known as the musician Grimes, and five - a set of twins and a set of triplets - with his first wife, the writer Justine Musk.

Elon Musk has a known nine children after recent revelations he fathered twins to a former employee. Photo / AP

Musk had previously expressed his feelings about having children on Twitter, posting: "Doing my best to help the underpopulation crisis. A collapsing birth rate is the biggest danger civilisation faces by far."