Scaffolding was reportedly stolen from a property in Richmond on Monday during the annual Meet parade.
The scaffolding was taken from a house in Hurgill Road near the Nuns Close Car Park at around 9am.
Floats were gathering at the time in the car park for the annual Richmond Meet procession.
Two males were seen removing the scaffolding and putting it in a vehicle, possibily an orange crew cab type truck.
Meet organisers spoke to the men as their vehicle was in the way but thought they had permission to remove the tubes.
Meet president Lorraine Hodgson has urged anyone who may have taken photos of the floats in the car park to pass them to police.
Anyone with information should call North Yorkshire Police on 101.