The US Patents and Trademarks Office has notified the Sussexes' lawyers of various issues, including incorrect classification of yoga blankets, picnic baskets and recipe books.

And the agency said that fees are due to various bodies around the world to register the trademark – totalling $11,382 (nearly £9,000).

It is believed that Netflix – which has just finished filming a cookery show with the duchess – is taking over the commercial exploitation of the brand, so it would be safe to assume it will pay the fees.

A spokesman for the streaming giant declined to comment on their deal with her this week. Representatives of the Sussexes were contacted for comment.