The Crown's Elizabeth Debicki reportedly lay in an open coffin when filming scenes as Diana, The Princess of Wales.
Netflix has been accused of going "way over the top" for ratings in scenes showing the aftermath of Diana's death in Paris in 1997, which reportedly include medics trying to save her in a bloody hospital theatre.
Elizabeth reportedly played dead as Diana, lying in a coffin, with a French priest administering the last rites in the scene.
Prince William and Harry will also be shown following their mother's coffin at her funeral in the reported heartbreaking scenes, it is understood.
The controversial moments are said to form part of season six of The Crown, it is believed.
An onlooker on set told the Sun: "They actually made Elizabeth climb into a coffin and play dead as Diana. Viewers will see a French priest administering the last rites for Diana as she is pronounced deceased."
They added that Dominic West, played by Prince Charles then enters the room in tears and notices that his former wife is missing an earring.
The Princess' two sisters then reportedly join Charles and the trio cry around the open coffin.
The onlooker added: "Princes William and Harry never saw their mother dead in a coffin and they shouldn’t have to watch this. Nor should the British public.
"The bosses went way over the top to chase ratings. Everyone was very uncomfortable doing the shoot. It is obscene and should be banned from broadcast."
The scene where medics attempt to save Diana after the car crash was also described, with blood everywhere, even on the door.
The witness also claimed that cast members were visibly upset about the scenes.
The Mirror has approached Netflix for comment.
The streaming giant told the publication that scenes of Diana's death were being handled with the 'utmost respect and care'.
This is the latest in a line of controversies surrounding The Crown, which chronicles the reign of Elizabeth II, and currently stars Imelda Staunton as The Queen, and Jonathan Pryce as Prince Philip.
Last month, a friend of the Queen, Lady Glenconnor, who acted as maid of honour at the 1953 coronation, said the show makes her "so angry" because it's a "complete fantasy' and is "so unfair on members of the Royal Family".
Lady Glenconner, 90, had known the monarch since she was a child and she also acted as a lady-in-waiting to Queen Elizabeth's sister, Princess Margaret, for more than 30 years.
She said what angers her the most is the fact that some people, especially American's who tune into watch the Royal drama, believe every scenario to be completely true.
Netflix has continued to defended the show, stating that it "has always been presented as a drama based on historical events".
