The Duke and Duchess of Sussex’s Spotify podcast deal is unusual for members of the royal family – and the pair are likely to face “bear traps everywhere” as they continue to pursue their own commercial activity, a royal author has warned.

Penny Junor said Harry and Meghan’s appeal stems, not from them as individuals, but because they are royal.

But she added they no longer benefit from “gold standard” advisers at Buckingham Palace, who would have checked their plans for pitfalls.

The couple have set up a new production company, Archewell Audio, and signed a multi-year deal with audio streaming service Spotify to host and produce podcasts.

Ms Junor said the couple’s other multimillion-pound deal with Netflix had already proved controversial because the firm produced The Crown, with season four exploring the troubled life of Harry’s late mother Diana, Princess of Wales.

The royal expert told the PA news agency: “I think unhappily, it is very difficult to square up being a member of the royal family with commercial activity because there are bear traps everywhere.

“I’m sure it never crossed Harry and Meghan’s minds about The Crown, possibly being negative or damaging when they got their wonderful contract from Netflix.

“But the problem is that they left those gold standard advisers when they left Buckingham Palace, when they turned their back on the help that they were getting.”

The Queen’s grandson Harry and former Suits actress Meghan quit as senior working royals in March for more freedom and to earn their own money.

They still remain members of the royal family, and retain their HRH styles, although they do not use them.

Ms Junor added: “Inevitably, because of who they are, there will always be a market for them.

“It’s not even because they’re Harry and Meghan, it’s because they are HRHs.

“That adds a huge number of noughts to the end of any deal that they do.

“That’s not their fault. It just highlights how difficult it is to square up being a member of the royal family but earning a living outside it.”

The Sussexes have settled into a new life in Montecito in California and bought an £11 million house.

As well as their Netflix contract and the Spotify deal, Meghan is establishing herself as an investor with a focus on supporting female-founded companies, beginning with investing in a start-up business which makes instant oat milk lattes.

Ms Junor added: “They’re living in an extremely expensive house with a lot of very expensive running costs and a very extravagant lifestyle.

“The big question when they moved was how were they going to support themselves?”

She said of the Spotify deal: “If this is a way of doing that – it’s unusual for members of the royal family but so is this whole situation – my feeling is, slightly, good luck to them.

“Don’t judge them until it’s all gone pear-shaped.”