A worried letter from six-year old Leo Park sparked a mammoth operation to test what is believed to be the world's first chimney specifically designed to accommodate Santa Claus.
The little boy's parents are having a house custom built and when Leo viewed the plans he was concerned that the chimney wasn't big enough for Father Christmas and his famous belly that shakes when he laughs like a bowl full of jelly.
As he was penning his traditional letter to Santa, Leo decided to also write a heartfelt missive about the chimney design problem to Jeremy Paxton, who owns the estate on which the new house is being built.
In childish scrawl the letter reads: Dear Mr Paxton, I am worried that my mummy's house does not have a big enough chimney. I think Santa Claus will get stuck. Please can you help. Love Leo Park.
Paxton, founder and owner of luxury holiday home development Lower Mill Estate in the southwestern English region of the Cotswolds decided to commission a special formula to satisfy Leo's concerns.
Obviously size was the key consideration to ensure Santa won't get wedged tight on his way to stuffing the stockings and so Paxton enlisted a mathematician to take on the challenge and save the jolly old elf from turning red for the wrong reasons.
The Santa-friendly formula looked at risk factors of chimney entry, the size of St Nick's girth versus the width of the chimney at its narrowest point.
To test what they said was the perfect chimney, Paxton enlisted the help of a stand-in Santa Claus in full padded outfit, a crane, a harness and winch to put the new chimney through its paces.
Leo was invited to watch as the great experiment got underway.
Go on Santa he shouted out as the faux Father Christmas was lifted into the air towards the chimney.
A few seconds later and Santa was successfully lowered into the chimney of the half-built house, re-emerging shortly after to deliver a hearty: Ho Ho Ho.
I can guarantee that this chimney is big enough for Santa and all the presents, he told Leo.
An excited Leo gave a thumbs up to the St. Nicholas impersonator and rushed to hug him.
I'm absolutely delighted not just that Santa fitted into the chimney, but that that little boy, Leo, said to me: 'That was the best day of my life' which made the whole thing worthwhile, said Paxton.
The Park family won't be able to inhabit their new holiday home until next December, just in time to get the milk and biscuits ready for their very special Yuletide visitor.
(Reporting by Georgina Cooper, editing by Paul Casciato)