Friends of Meghan Markle and Prince Harry say in a new chapter of an unofficial biography about the pair that the Queen has not taken “full ownership” of the concerns they addressed during the Oprah interview.

In a March interview with Winfrey, Harry and Meghan made a series of explosive allegations against the royal family, accusing an unnamed royal – not the Queen or the Duke of Edinburgh – of racism, the institution of failing to support a suicidal Meghan, and touching on their tumultuous relationships with the Prince of Wales and the Duke of Cambridge.

After the interview aired in the UK, Buckingham Palace issued a statement from the Queen, which read: “The whole family is saddened to learn the full extent of how challenging the last few years have been for Harry and Meghan.

“The issues raised, particularly that of race, are concerning. While some recollections may vary, they are taken very seriously and will be addressed by the family privately.

“Harry, Meghan and Archie will always be much loved family members.”

According to excerpts published in People Magazine, authors mid Scobie and Carolyn Durand think Her Majesty did not take “full ownership” and that “little accountability” has been taken.

It said: “The Queen’s ‘recollections may vary’ comment ‘did not go unnoticed’ by the couple, who a close source said were ‘not surprised’ that full ownership was not taken. ‘Months later and little accountability has been taken’, a pal of Meghan added. ‘How can you move forward with that?”’

Harry and Meghan have been on parental leave since the birth of their daughter, Lilibet, in June, but the book’s co-author, Omid Scobie, told People that they are “really excited” about the next stages in their public lives.

He described the pair as being “in a healthier place” as they approach “the era of visibility” and plan to expand their in-person work with their Archewell Foundation this autumn.

Despite the fact that Meghan and Harry were not interviewed for the first version of the book and did not participate, the writers have stated that they spoke to the pair “when appropriate”

Meghan admits to giving information to the writers to “prevent any further misrepresentation” in documents disclosed as part of her High Court lawsuit over the publishing of a letter to her father.

“She indicated to a person whom she knew had already been approached by the authors that the true position as above (which that person and several others who knew the Claimant already knew) could be communicated to the authors to prevent any further misrepresentation,” her lawyer said.

Scobie’s book, which he co-wrote with colleague Carolyn Durand, will be reissued in paperback on August 31 with a new epilogue. “Meghan famously spoke about that it was not enough to survive – we are now in the thrive chapter,” Scobie told the magazine.

These latest remarks indicate that the Duke and Duchess of Sussex do not feel the Palace has made any progress since their scathing interview.

On Tuesday, the Queen’s grandson Harry and former Suits actress Meghan published a long statement on the Archewell website, expressing their grief over the status of the “exceptionally fragile” world and claiming the catastrophe in Afghanistan had rendered them speechless.