According to publishers, Prince Harry's book Spare has become the fastest-selling non-fiction book in British history, according to journalist Omid Scobie.
"It's, so far, recorded a sales figure of 400,000 copies across all formats," he said.
According to Scobie, a representative at Trans World Books, a branch of Penguin Random House in the UK, gave him the information about the book.
The writer of Prince Harry and Meghan Markle's unauthorized biography said, "Finding Freedom was the fastest-selling royal book in two decades. Grateful to have experienced that and thank you again to everyone who read it."
In his book, Prince Harry has made some severe claims about the royal family that were leaked online a few days prior to its formal release on Tuesday.
Days after Harry and Meghan broke their silence in their Netflix documentary, the book was published.