Grimes and Elon Musk have welcomed a baby boy.

The founder of Tesla and Space X announced that the 32-year-old singer, real name Claire Boucher, had become a first-time mum on Monday, when he told his Twitter followers: "Mom & baby all good".

He later returned to the site to answer some questions, with him telling one follower that the child was a boy and his name was X Æ A-12 Musk, although it is unclear if this was a serious comment.

After users urged him to share a picture of the baby, the 48-year-old posted a close-up snap of the newborn lying down while wrapped up in a blanket and wearing a hat. However, he put a filter on the snap so it looked like the tot had face tattoos. When someone said they liked the filter, Elon replied: "Thanks :) Never too young for some ink haha."

Another user followed up by asking for a photo of him holding the baby, and he happily obliged.

The baby boy is Grimes and Elon's first child together, but he is also dad to five children from his marriage to Canadian author Justine Wilson.

Back in March, the star revealed she had given up her strict vegan diet and was craving cow's milk and butter while pregnant.

In a video for Harper's Bazaar, she confessed, "Lately the one pregnancy craving I have is just a glass of milk. Which is so weird because I haven't had a glass of milk in probably 20 years, but lately I've just been having a glass of milk. Just cow's milk. It's probably become clear I'm not vegan during this time."

Grimes and Elon have been in a relationship since May 2018.