Vale Primary School pupil Julian Bougourd made the whistle over a couple days with his father, using wood from the garden.
He had been inspired after seeing similar instruments while on holiday.
'I had never made a whistle before,' he said.
'It was quite hard, especially to make the mouthpiece.'
Proud of his creation, he entered it in a children's craft class at the North Show on the Tuesday night.
Along with his mum, Ghislaine, he went to look around the tent on Wednesday and, although he was disappointed to not win a prize, he looked forward to having it back.
But when family friends went to pick up the whistle after the show, it had gone.
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