Meghan told Thomas Markle he posed a danger to children in hospital letter

The Telegraph and the Sun first reported the letter’s contents, and the Duchess’s spokesman later confirmed them when approached by GB News. GB News has sought comment from Mr Markle Sr.

Neither the Duke nor the Duchess is understood to have pursued any follow-up action with police regarding Mr Markle Sr.

Meghan has reportedly expressed concern that no action had been taken by the Met Police to alert other authorities, raising serious questions about investigative opportunities that may have been lost.

Meghan first became aware of historic allegations against her father in January 2019, when police shared with her a letter penned by a whistleblower with connections to the Markle family.

The correspondence, which had been directed to a specialist unit within the Metropolitan Police, allegedly contained deeply disturbing claims about Thomas Markle Sr’s conduct towards children.

Sources close to the Duchess say she wished to go public with the information straight away, but was counselled by officers not to do so.

The whistleblower’s letter was never forwarded to law enforcement in either the United States or Mexico, where Mr Markle Sr was residing at the time.

Its date was originally reported as summer 2018, though this was later corrected to January 2019 after the Met located a copy in its records.

Thomas Markle Jr has reportedly submitted a sworn affidavit setting out allegations of widespread child sexual abuse perpetrated by his father.

Mr Markle Sr has categorically denied every accusation levelled against him describing the allegations as “sick lies” and saying he “could never do what [he’s] being accused of”.

Speaking to the Mail On Sunday, he stated: “I have never had sex with anyone under the age of 18. I have not had my computer or phones for nearly two years. If there is anything bad on there it was put there by someone else.”

As the mother of Prince Archie, now seven, and five-year-old Princess Lilibet, the Duchess is said to have found the claims involving young children especially distressing to absorb.

Although she did not identify the allegations from her own personal experience, it is said that they helped her understand aspects of her family’s dynamics that had previously been difficult to explain.

Meghan has said she hoped that others could understand why she was estranged from her father. GB News has sought comment from Mr Markle Sr on this.

For years, the public explanation for the estrangement between the Duchess and her father centred on his decision to stage photographs with paparazzi ahead of her 2018 wedding and his subsequent refusal to apologise.

It is now clear, however, that far graver concerns lay behind the severed relationship, kept secret for more than six years.

Both the Duke and Duchess have spoken publicly about Mr Markle in the intervening period without ever alluding to anything beyond the tabloid photograph dispute.

The Duchess is reported to be devastated by the full scope of the claims that have now surfaced, yet simultaneously feels a measure of relief that they can at last be properly examined and that the true reasons for cutting ties with her father are finally in the open.