A constant cause of concern facing all food manufacturers is that, no matter how tamper resistant the packaging they use for their products might be, it is always possible to interfere with them usually as a prelude to demanding large sums of money to indicate where the contaminated packs have been placed. Usually, those intent on tampering with a product take it away from the outlet where they bought it so they can open the pack or container, contaminate the contents and conceal what they have done before returning it to the shelf. In a few cases, theymight attempt to insert a foreign body into the pack while they are still on the premises but this increases their risk of being detected.