Does Heresay Exist?

In the security clearance realm, is there something like or a concept of heresay? If someone tells me something about someone else (and I have no idea if it is true or not), do I have to report it? What if it is something in the past?

Seems along this lines of this thread: How to Report Another Clearance Holder

I would take the responsibility of “See something, say something” serious. If you hear something…report it. Let the FSO take it from there. An anonymous letter under the door is one way. As long as your conscience tells you it was reported…you have no need for polygraph worries. If you feel you did not do enough…you will remember that on poly day. Trust me. And that causes problems.