Prince Harry's new memoir is part of a lucrative four-book deal, one of which won't be released until after the Queen has died, it has been claimed.

The Duke of Sussex's announcement this week that he had penned a memoir about life in the Royal Family is just the "tip of the iceberg", according to industry insiders.

Following something of a bidding war among publishing houses, the final figure is understood to have reached up to £29 million after a reported starting point of £18million, set by Harry himself.

The initial book, announced on Wednesday, is due for release by Penguin Random House next year, coinciding with Her Majesty's Platinum Jubilee celebrations.

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The Royal Family
The final book is understood to be being saved until the Queen has passed away

The Duke's wife Meghan Markle is set to write a wellness guide as part of the contract and he will write a second, while little is known about the final title or who will write it.

Harry, 36, is said to have "led" negotiations over the deal from his home in California with two publishers understood to have flown to London to meet him.

Others then participated in an online auction, it has been reported.

The deal comes with Harry and Meghan, 39, having already signed multi-pound deals with the likes of Netflix and Spotify after stepping down as senior royals in March 2019.

Meghan Markle and Prince Harry
Meghan is set to write one of the books as part of the deal

A publishing insider told the Daily Mail the prince's negotiating style was of the "take it or leave it" variety.

"Those involved were actually very shocked by his approach, which was to look at them coldly and state his demands: $25million," they explained.

The source said the "most shocking" part of the deal is that Harry will wait to pen his second book until after his grandmother has died.

"People [will] start asking, naturally: what has he got, who is he going to target?" they said, adding it appeared in "very bad taste".

The Firm is said to be concerned by the Duke's decision to collaborate with ghostwriter JR Moehringer on what Penguin described as "the definitive account of the experiences, adventures, losses, and life lessons that have helped shape him".

Harry himself said it is a "wholly truthful first-hand account" of his life.

But Palace aides fear it will only do further damage to Harry's relationship with his family.

He and Meghan have already made multiple damaging allegations since stepping aside, including during their interview with Oprah Winfrey in March.