It sounds like you're requesting a document for legal purposes(?), which would be beyond the scope of the support we can offer here... I can confirm that a blurred face in rendered media, cannot be un-blurred, without access to the (un-blurred) source media.
I struggled with how to respond to this. I don't know the intent of the person asking, so after considering a response. I will say that technology was created in Germany as early as 2006 that can undo certain kinds of attempts to hide a face, and its exceptionally good software.
I would suggest if you're in a position that there is legal jeopardy attached to how to respond to those asking you this you may want to consider better research than asking in this forum.
Bruces response should be understand as Adobe doesn't make a tool.