There are occasions when less reputable suppliers will make "cold-calls" and try to check up on whether you need more of an item, eg photocopying paper, or say that they've lost the order that was sent through and could they have the number again. These may be bogus firms seeking to supply goods that you never ordered or do not need. Sometimes the prices charged are excessive, however, if the firm can quote an official order number it may be very difficult to argue that no contract exists. If it is not a supplier that you know you deal with be very careful about confirming details about existing or potential needs.
If in doubt, get them to send their enquiry in writing and check it out before giving any information. If the firm is legitimate, they will not have a problem with you being careful. There have been instances of departments being duped into buying, relatively low value, consumable items for over 10-times their market price or others signing up to lengthy contracts for equipment or services.
If in doubt at all, check with your Head of Procurement.