if you know his name and where he may live say nottingham, 192.com holds a serious amount of information about people. you do have to pay to view the info but think its only a few quid.
Typing in my name and the city i live in bought back my age range who i live with for free, for a few quid it will let me view everything.
there are sites that claim to be able to tell you but want £30, try and befriend a BT engineer see if they can help
