You might need to return to study (to obtain a doctorate) first. Most universities list their staff (together with their academic quailifications) on their websites. In fields such as law, almost all academic staff will have qualifications and/or experience beyond masters level.
This link gives some rather basic information but you migt be able to find out more by contacting the bodies listed at the bottom of the page:
http://www.learndirect-advice.co.uk/helpwithyourcareer/j obprofiles/profiles/profile421/
I also suggesting writing to the current holder of the Chair in Law at the university which you graduated from and seeking their advice. (Contact details will be on the university's website).
Chris