Princess Diana was known for her cheeky sense of humour – but an explosive new book claims her fondness for having a laugh led her to pull a cruel prank on American talk show host, Oprah Winfrey.

In a new chapter of his popular book Battle of Brothers, royal author Robert Lacey claims Diana “never had much time for” the veteran broadcaster. During the mid-1990s, Lacey writes, Oprah was keen to secure a one-to-one interview with the Princess of Wales – and even flew to London to try and convince her.

According to Lacey, that’s when Diana decided to play a little trick on the host and invited her to Kensington Palace for lunch. At the time, Oprah had recently showed off her weight loss, dropping about 40lbs through a new diet. When inviting Oprah to dine with her, Diana reportedly asked her personal chef Darren McGrady to prepare his tomato mousse – a speciality of his.

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Oprah Winfrey came to the Palace to try to secure an interview with Princess Diana ( 
Image:
Getty Images for Global Citizen)
As the talk show host tucked into her lunch, she apparently asked the Princess: “Diana, how do you stay so slim eating rich food like this?” Diana replied explaining she ate small portions and worked out regularly – but all was not as it seemed. In careful instructions to chef McGrady, Diana asked him to give her the fat-free version of the famed tomato mousse, while serving Oprah a full-fat version laced with heavy cream and mayonnaise.

Lacey claims the chef said: “Diana never did tell the truth.” Simone Simmons, a friend of the Princess, tells Lacey: “Diana felt very uncomfortable with Oprah. “She thought that Oprah was only after sensationalism – like when she interviewed Fergie about her book, and all she wanted to talk about was Diana.”

The Princess was reportedly concerned Oprah wanted to speak to her to increase her ratings. However her son Prince Harry and daughter-in-law Meghan Markle clearly had more trust in the TV legend, and sat down with her for a tell-all chat about their time in the royal family.

The made several shocking claims about The Firm, including that someone asked about Archie skin colour. Meghan also said that the Duchess of Cambridge made her cry and claimed she was refused help for her mental health despite being suicidal.