According to The Times, the money raised will go to Elephants Without Borders, an organisation that helps to track and protect the animals from poaching.
The British newspaper added: "However, it also touches on sensitive areas, allowing room for accusations that the couple are cheapening the royal brand and will compromise themselves for money. According to one report, during tense talks before Christmas senior members of the royal family accused the couple of already signing a deal with 'firms including Disney'."
According to UK paper the Evening Standard, the Duke and Duchess of Sussex's plan to step down as senior royals began when Harry called his father on Christmas Eve to tell him that the pair wanted to make their move away from the family.
While he and Meghan wanted to live primarily in Canada, they wanted to keep their home in Britain, Frogmore Cottage, Harry explained, and planned to find commercial work to help them achieve financial independence.
Charles – who was holidaying with his mother, the Queen, in Sandringham at the time –reportedly told Harry he needed more than just a vague idea of splitting from the family that raised him if he was serious about the move, and insisted he email Charles a detailed plan of how it would actually work.
Clearly, the pair were eager to get the ball rolling, as they sent through their draft proposal days later – and, according to palace sources who spoke to the Evening Standard, it was "completely incoherent".
While Meghan and Harry were keen to embark on their new 'independent' life as quickly as possible, the palace also had questions other logistical questions around the couple's immigration status in Canada and whether or not the pair already had commercial deals in place.
There were "complex implications" of the Sussexes plan, and Charles insisted the whole thing needed more time to be nutted out – and it had to be done in person.
"It reached an impasse where his father said, ‘We need to have these conversations in person. This is not something we can negotiate over email,'" a source told UK paper The Times.
Harry agreed, but out of respect for the Queen, also wanted to speak to her about his plans.
Despite initially welcoming to a visit from her grandson, the Queen was unavailable when he came to call – but made it clear that Harry and Meghan were not to announce their plans yet.
Clearly the request fell by the wayside, the prince making his official public announcement on the afternoon of Wednesday, January 8 in Britain – a move that the Evening Standard reports "deeply upset" the Queen, who responded with her own statement.
"Discussions with The Duke and Duchess of Sussex are at an early stage. We understand their desire to take a different approach, but these are complicated issues that will take time to work through."