Piers Morgan remains unconvinced Earl Spencer wrote his book for Diana

Earl Spencer, Princess Diana's younger brother, wrote a bombshell memoir that reportedly caused an upheaval in royal circles.

So much so that Buckingham Palace - which mostly refrains from commenting on claims published in books - had to issue a statement.

When asked about his motive for writing the book, His response was plain.

He said he penned the memoir for his sister, Diana.

But Piers Morgan is unconvinced. Earlier, Spencer had to apologize to him for wrongly claiming that.

He claimed it was the British commentator who published intrusive photos of Diana, back in 1993 when he was the editor of the Daily Mirror.

But Morgan was not the tabloid's editor at the time. David Banks was.

He later joined as editor in 1995.

In response to the false claim, Morgan sued Spencer and his publisher of Swan Song: Diana.

The author, admitting his mistake, apologized to the journalist but also took a thinly veiled dig at his critics.

"Unlike some journalists we know, I’m very happy to acknowledge I made a small error and I’ve apologised for it, and we’ll put it right in the second edition," Spencer told ITV.

Morgan, however, still argues that Diana would not have wanted her brother to write a book that would have been viewed as an attack on King Charles at such a time.

“She wouldn’t want a savage attack on King Charles, with her boys at the state they are in their lives," he told The U.S. Sun.

Then, he brought Prince William, claiming he must not be content with the contents of Spencer's book.'

“I would love to know what William thinks of all this, because I suspect he’s deeply, deeply unhappy about all this stuff being regurgitated and a fresh attack on his dad, who’s got cancer, is 77, is the King, and is doing a really good job as our Monarch."

Meanwhile, the Swan Song: Diana has hit the shelves.