Canadian singer Claire Boucher, also known as Grimes, has taken legal action against billionaire Elon Musk regarding the parental rights of their three children.

On September 29, Boucher filed a “petition to establish parental relationship” at a California court, as revealed in documents obtained by Page Six.

This petition is typically used when the parents are unmarried and seeks a court declaration of the children’s legal parentage.

The contents of the documents remain sealed and undisclosed to the public.

The lawsuit follows Grimes’ recent plea to Musk to allow her to have access to their third child, whose arrival was kept secret.

This plea was made through now-deleted tweets in response to pictures of Musk’s twin children shared by Walter Isaacson, the author of Musk’s biography, and Shivon Zilis, an executive at Neuralink.

“Tell Shivon to unblock me and tell Elon to let me see my son or plz respond to my lawyer. I have never even been allowed to see a photo of these children until this moment, despite the situation utterly ripping my family apart,” she wrote in the tweet.

Grimes and Musk were in an on-and-off relationship between 2018 and 2021. She gave birth to their first child, X, in 2020.

They Secretly Welcomed another child, Exa via surrogacy in 2021.

The “Elon Musk” biography published in September 2023, revealed that the singer and tech mogul secretly welcomed another son, Techno Mechanicus. His year of birth was not named in the biography.