When his son, Prince William, struggles to fasten one of the ceremonial robes, Charles tells him not to worry, as he does not have "sausage fingers" like himself, the BBC cited the then 74-year old monarch as saying on camera.

British tabloids ran stories, ranging from lengthy explainers to more light-hearted takes, focusing on Charles' fingers in the days leading up to the historic ceremony earlier in the year.

Some even brought in doctors to weigh in on whether there may be an actual cause for concern about the new monarch's chubby digits. Speculations have ranged from oedema and arthritis to infections and allergies.

Internet searches for "sausage fingers" peaked in the run-up to the May 6 ceremony in Britain, according to data from Google Trends.

The 90-minute documentary, which had private access to follow the first year of the new reign after the death of Queen Elizabeth in 2022, is due to air the day after Christmas, or Boxing Day, as it is celebrated in Britain.

It features Justin Welby, Archbishop of Canterbury and the spiritual leader of the worldwide Anglican Communion, forgetting his lines during a rehearsal.

"I have a memory that is probably about as good as our spaniel - in other words zero," Welby says, about not knowing the words.

(Reporting by Muvija M; editing by Sarah Young)