Yes it is possible. You are referring to IP 'spoofing'. Nevertheless it is extremely difficult and equally dangerous. Some info is given here:
http://www.linuxgazette.com/issue63/sharma.html
You can also try and do a google search, like here:
http://www.google.com/search?q=IP+address+spoofing

I am sure that you are trying to investigate a fraud done on yourself and I fully empathise with you. However, if by anychance you are trying to gather information for your own reasons, I must warn you that this is not permitted /illegal, according to the TOC of EE. Please be informed.

By the way, don't you have a firewall?

Did you think it could be done from your own system? (IE some one has taken contorl of system)

How did some one get your info to make the purchase ?

amirinamdar Thank you for your answer but how is it "extremely difficult and equally dangerous"  I can understand why it could be difficult not knowing that much about computers and how they work, but Dangerous why?  Would the computer or my LAN be at risk?
Also your comment has puzzled me "I am sure that you are trying to investigate a fraud done on yourself and I fully empathise with you. However, if by anychance you are trying to gather information for your own reasons, I must warn you that this is not permitted /illegal, according to the TOC of EE. Please be informed."  Well obviuosly I am trying to see what has happened, why would and how would I be trying to gather information for my own reasons?
By the way, don't you have a firewall? yes believe it or not I do have a firewall but my son is networked to this computer and we share the internet and he says the firewall stops msn and his games to work.  So he frequently disables it and my computer has been left on all night without my knowledge and connected to the internet,  I was stupid (naiive)  enough to think that I had no information on my PC that was worth stealing but boy was I wrong, I have been informed by a friend that the computer spies on you and secrets info from places you have been and anyone can gain accress to it.  So he says that places I have been shopping and keyed in my bank details can be there on my pc for the whole world to see he says to go on the internet you need spyware to stop your details from being disclosed and that its best to keep all of your private stuff saved on a cd and not on the pc and he has shown me how to keep my secret info secret.
in the past my son has mentioned to me that sometimes when he plays games on the PC his ping skyrockets (now this to me is a foreign language) and is showing activity on the line such as downloading and he will ask me if I am downloading something but I used to think nothing of it and just say no!  But it seems that maybe this could have been when someone was using my computer to download stuff via the internet onto theirs.  I would never have though this was possible untill I read into on the internet and this has got me worried,  I have had goods ordered in my name and sent to my address and charged to my card but they weren't mine, I never ordered them could these people therfore know where I live?
 

Oops.. sorry liddler, I didn't see your post >>>https://www.experts-exchange.com/questions/20975384/Standard-response-material-re-Spyware-Adware-BHOs-and-other-Malware.html