How do i track the person who is accessing my email account?

someone has figured out my password and is now accessing my email account ... its a yahoo account ... is it possible in australia to track this person
How do i track the person who is accessing my email account?
In most cases people change the password or change their email address with a stronger password,


To give it a shot you could contact yahoo %26amp; see if they could look %26amp; see which IP address its coming from, (if yahoo is cooperative) after that you could then contact the ISP security department to see if they can give the information of the user of the IP address.