I've run into this a couple of times, more or less. You are not going to get
anything more >from him. Instead, I suggest you go around him.

What information do you need? Get it >from his mother, your first cousin. Or
call a sister or brother of his, don't tell them of your run-in, and get the
info >from them.

If you hit a brick wall in the form of an uncooperative relative, go around,
under or over the wall. :-)

Sam