There's one called "The Body" by Richard (Ben) Sapir written in 1983 or so, which is about an archeologist who discovers what appears to be the remains of Jesus in a site in Israel. There's lots of intrigue over whether it should be made public knowledge, as it would have all sorts of implications for various powerful religious organisations. I think this could be the one you're after - the same author wrote another book ("The Far Arena") about a Roman centurion found in a block of ice who is thawed out and brought to life in the present day. "The Body" was recently filmed with Antonio Banderas and Olivia Williams (it's on Sky Movies from time to time - next showing 2330 03/11 SP4, and can be found in most rental stores). The book is o/p in this country, though Amazon list a few used copies. Couldn't find a synopsis for the book (my copy is in storage, and I read it years back), but here's the IMDb page for the movie:
http://www.imdb.com/title/tt0201485/
. Hope this is the right one!