Prince Harry - who recently honoured her late mom Princess Diana - is "torn" between Meghan Markle and the Royal Family - after "sacrificing everything" for his wife, claimed a royal expert.

Duncan Larcombe - author of "Prince Harry: The Inside Story" - claims the Duke and Duchess of Sussex may face a fight for their marriage unless the couple can "compromise".

The author  claimed that Harry will feel conflicted after meeting brother William in London last week for the unveiling of a statue dedicated to their beloved mom Princess Diana.

Duncan, in conversation with Closer magazine,  said: "Harry and Meghan seem to think they can co-exist in these two worlds – the world of British royals and American celebrity." He added, "The Duke is loving the American life now – but he’s still in the honeymoon phase."

The expert added: "I think coming back and seeing his brother, especially against the very moving backdrop of a memorial for their mother, will maybe make Harry question what he’s given it all up for."

The Duke and Duchess of Sussex announced last January they would step back as "senior" royals and work to become financially independent.

Prince Harry and Meghan Markle, who now live in California, formally stepped down in March last year, with a plan to review the arrangements after 12 months.