This may seem random but I will explain shortly. If you ran/run a hosting company and a customer is concerned as one website is getting GBs worth of traffic when it is more used to a few hundred visits a month... How would you support them?
It sounds like you might be worried that the traffic is illegitimate. If that is your concern, I would want to find out the IP addresses of the requests and see if they have anything in common. It could be a small-scale ddos, or just an attempt to use your bandwidth. Furthermore, I would look at the specific content they're requesting from the logs. Is there a particular page or file that is being requested more than normal?
If you're concerned with the extra bandwidth charges, does your host suspend your account when you exceed the bandwidth limit, or do they charge for overages? You may want to see if you can temporarily upgrade to the next package so that you don't exceed your bandwidth limit if you think the extra traffic is legitimate and don't intend to block it.
All great ideas. I had already disabled hot links... No joy.... I have just upgraded WordPress in case there was a vulnerability that was being exploited. I have also disabled the commenting too to see what happens. Thanks again. I will report back.
Your going to first want to try and at least see where this traffic of yours is mainly coming from. You mentioned something amour china most us hosts and sites usually block all China ips from their servers so that they don't run into problems such as this one.
Try upgrading all your software on the server / account. Also find out with your host if they will suspend your site or does overselling kick in if you so happen to hit your bandwidth limit. Next upgrade your plan for the next couple days or month just incase your bandwidth does so happen to go above your allocated resource limit so that then you won't get any head aches then.