Kind of a sticky issue here. I am assuming that you are concerned about disclosure to whomever might purchase the home. I hope that I am correct.
Maybe there would be an open house in the near future?
If there is a open house sometime, you might want to go in and ask questions the realtor yourself, not about any disclosure, but about whether there are any leaks. Or, have some friends that you know, but the owner doesn't and have them go to the open house.
Just an idea.
I had a similar problem when I bought my home. I asked about leaks in the basement. He said that he had "detected" moisture from time to time. Well, to make a long story short, it was very detectible and quite much more than moisture as the years went by after I purchased it.
A few sites that do address some of the legalities concerning issues like this, are listed below.
Wet Basements - Should You Buy a House With a Wet Basement? - Spotting Inherent Wet Basement Problems
New Home Has Water Problems - Real Estate Advice - Home Inspection
http://www.weloveaustin.com/sellers/...isclosure.html