A member of the public first reported the van on Monday, January 14, collecting charity clothes bags in Cardowan Road, Stepps.
Two men were spotted placing a transferable cancer charity sticker onto the side of the van. A similar van was also reported to have been seen operating in the Millerston, Muirhead and Chryston areas throughout the day.
Police can confirm that no cancer charity vans were operating in these areas during this period.
PC Michael Duffy, of Cumbernauld Police Office, said: “Charitable organisations rely very heavily on the generosity shown by the public.
“It is unfortunate that there are people out there who are more than happy to steal from these charities.
“My advice would be to check the collection day noted on the bag before leaving it at your door.
“Householders should not be embarrassed to ask collectors to identify themselves as they collect clothing.
“Being pro active within our communities is a good way of deterring perpetrators and preventing crime.”
Witnesses are urged to contact Cumbernauld Police Office on 01236 503 900.