I was reading this question, Would Voldemort's Taboo Spell Trump the Fidelius Charm?, and I thought to myself if the secret is kept in the soul, what happens if it's split?
‘An immensely complex spell,’ he said squeakily, ‘involving the magical concealment of a secret inside a single, living soul. The information is hidden inside the chosen person, or Secret-Keeper, and is henceforth impossible to find – unless, of course, the Secret-Keeper chooses to divulge it. As long as the Secret-Keeper refused to speak, You-Know-Who could search the village where Lily and James were staying for years and never find them, not even if he had his nose pressed against their sitting-room window!’
Prisoner of Azkaban - pages 152-153 - Bloomsbury - chapter 10, The Marauders Map
What happens if that soul then becomes lodged in someone or somethign else? Could the secret be found out that way?