Police are looking into 'The case of the mysterious vanishing Harry Potter props', after the disappearance of a number of items from the set of the upcoming film.

Apparently no one noticed the thefts until items used in the filming started magically appearing on auction site eBay, advertised for thousands of pounds. According to reports, wizards' hats, magic wands, gold coins, Hogwart's School blazer badges and tie pins, which were given to thank stuntmen, have all appeared on the site.

But just as mysteriously, since Hertfordshire police got involved the props have vanished back into mid air.

The only piece of film-related memorabilia up for sale on eBay at the moment is a gold pocket watch of which only a hundred were made and given to the cast and crew of the film. The watch carries the Hogswatch school emblem and is currently offered at $200.

Harry Potter and the Philosopher's Stone opens later this month.