The book, Finding Freedom, claims the Cambridges and Sussexes barely spoke in Commonwealth service at Westminster Abbey in March, although they have not seen each other since January.
The authors of the book, Omid Scobie and Carolyn Durand, said: ‘Although Meghan tried to make eye contact with Kate, the Duchess barely recognized her. “
Mr Scobie told The Times: “For willfully snubbing your sister-in-law… I don’t think it left a good taste in the couple’s mouths. ”
Finding Freedom, serialized by The Times and The Sunday Times, contains sensational new claims about how Meghan and Harry’s relationship with her family fell apart and how the Sussexes decided to leave life as members of the Royal family.
TV footage from the March 9 service showed the Cambridges and Sussexes exchanging an awkward ‘hello’ as they took their seats.
It was Meghan and Harry’s last public royal duty before stepping down, and the first time the couples had appeared in public together after Megxit’s announcement.
The authors of Finding Freedom, accused of being Sussex cheerleaders, describe a culture of growing tension between the couple and other members of the royal family.
They say the Sussexes felt their complaints were not taken seriously and that other royal homes were leaking stories about them to the press.
“There were only a handful of people working at the palace whom they could trust,” the authors write.
“A friend of the couple called the old guard ‘the vipers’.
“Meanwhile, a frustrated palace staff member described the Sussex team as the ‘squeaky third wheel’ of the palace. ”
Harry and Meghan “liked to be in control of their narrative” in the early days of their marriage, the authors say.
But being told to operate under the aegis of Buckingham Palace after separating their household from the Cambridges was “a great disappointment for them”.
“As their popularity grew, Harry and Meghan’s difficulty in understanding why so few people inside the palace were looking out for their interests increased. They were a major draw for the royal family, ”write the authors.
The book says the Sussexes even considered breaking protocol by issuing a surprise visit to the Queen when they believed they were barred from seeing the monarch.
A spokesperson for Harry and Meghan said the couple did not contribute to the book, but did not deny the contents of the excerpts from The Times.
The spokesperson said: “The Duke and Duchess of Sussex were not questioned and did not contribute to Finding Freedom.
“This book is based on the authors’ own experiences as members of the Royal Press and their own independent reporting. “
The revelations come after the Sussexes launched legal action in Los Angeles after drones were allegedly used to take pictures of their 14-month-old son Archie.
A lawsuit filed in Los Angeles County Superior Court on Thursday claims that an anonymous person photographed Archie at her home during the lockdown.
The lawsuit alleges the couple were stalked across North America by paparazzi and targeted with relentless intrusions into their privacy.
Harry and Meghan – who left the royal family in March, saying they wanted more privacy – “aren’t seeking any special treatment” and only want the right to privacy, the lawsuit says.
The couple said they have “done everything in their power to stay out of the spotlight” except for their work, which they say is newsworthy.