The Duchess of Sussex has said she was informed about "disturbing allegations" about her estranged father in 2018.
In a statement, Meghan said a letter containing allegations against Thomas Markle was sent to the Metropolitan Police that year and subsequently shared with her.
Her comments come after reports that images of child sexual abuse allegedly belonging to her father had been found at his former home in the Philippines, which she said were "deeply" distressing.
In an interview with the Daily Mail, Thomas Markle, who is based in the US, denied possessing child sex images, calling the accusations "sick lies".
Commenting after the allegations, first reported by The Sun newspaper, the duchess said: "I am deeply distressed at the news that has come to light in the last 24 hours, and my thoughts are with any children who may have been harmed."
She said that when she received the letter outlining allegations against her father, she was "given assurance that these were being investigated".
She added she hoped it could be understood why she had kept her distance from her father and did "not allow him to have contact with our children".
This was "to protect them", Meghan said, adding that she had "trusted that the authorities were doing the same for other families".
She described the allegations as "more sickening than one could ever imagine" and said her "sincerest hope is that justice will be fully served and that the priority remains the safety and protection of innocent children".
The BBC has contacted Thomas Markle and the Metropolitan Police for comment.
The allegations about Meghan's estranged father cast a new light on their complicated family relationships.
The statement from the Duchess of Sussex says the sharing of information about Thomas Markle happened in 2018 - the year in which she married Prince Harry.
The claims add a fresh dimension to the questions about why Prince Harry and their two children did not ever seem to have met Meghan's father - and why relations seemed to be so strained.
It is not clear whether the police information about Thomas Markle was shared before or after Meghan and Harry's wedding.
With such question marks over her estranged father - and he has denied any wrongdoing - it also raises the issue of whether that played a part in the Sussexes' hurried return to the UK in late summer.
The Sussexes' spokesman has not responded to questions about whether that was a factor in their decision to leave the US, where her father was living.
Meghan is the only child of Thomas Markle's marriage to her mother, Doria Ragland, but he has two other children - Samantha and Thomas Markle Jr - from an earlier marriage.
The relationship between Meghan and her father, a former TV lighting director, broke down in the run-up to her wedding in 2018.
At the time, Thomas Markle was found to have colluded with photographers, accepting payment to stage photographs of him preparing for the wedding.
The resultant fall-out saw him pull out of his daughter's wedding, citing health problems. Meghan was instead walked down the aisle by King Charles III - then Prince of Wales.
In 2025, Thomas Markle moved to the Philippines after a series of strokes.
He is reportedly now living in a rehabilitation centre in Florida, where he is learning to walk again, after having a leg amputated during surgery in December 2025.