[Stays silent for a moment, going through all kinds of different possibilities in his mind]
It depends on how they were taken. Memories can be stored, so this world can be hiding them somewhere... when they are found, they will return to the owner automatically, unless a spell has been placed on them to stop that from happening.
But if they have not been taken, simply suppressed so we can't access them... the body will remember what the heart forgets.