Rogue email address.

I have an email address in my hotmail contacts which I can see if I create a new message and type k into the search bar it brings up all contacts with a K in the name which I can then click to add to the mail recipients. However if I go to contacts from the drop down menu this particular address is not in my contacts beginning with K. I have searched using different search engines for various parts of this email address with no success. It does not come up under any AV search but I would like to know how to delete this address when the only time I can see it I am not given any option to delete it. Ideas appreciated please.