According to The New York Times, the news was revealed in the business tycoon's biography penned by journalist Walter Isaason, who was given permission to look into Musk's life for the past two years. The book, which is slated for release on Sept. 12, will shed light on how Musk has struggled to build long relationships with his spouses, children, and collaborators, despite achieving incredible success in space exploration and electric cars that has made him one of the richest people in the world.
According to the NYT, the former couple's newborn goes by the nickname Tau.
The 52-year-old Tesla and SpaceX CEO now has a total of 10 kids with three different women.
Entertainment portal Page Six reported that Grimes, a Canadian musician, welcomed their firstborn, X Æ A-Xii, nicknamed “X” in May 2020 as well as daughter Exa Dark Sideræl Musk, nicknamed “Y” and a question mark via surrogacy in December 2021.
They also kept the birth of Y "under wraps until three months later."
When asked why they decided to keep it a secret in an interview on Vanity Fair (VF), Grimes said: “I don’t know what I was thinking.”
The outlet reported that she and the businessman called it quits when the VF cover story was released in March 2022. They had an on-and-off romance. While they said they had a “cool-off period” in September 2021, Grimes referred to their relationship as "fluid."
Aside from Grimes, Elon has five children with his ex-wife Justine Musk: twins Griffin and Vivian as well as triplets Kai, Saxon, and Damian.
The Tesla co-founder also welcomed twins with Shivon Zilis in November 2021.