I studied accounting. We were told that Internal Control, audits, reviews etc. are the silver bullets to curbing corporate corruption and accounting scandals. When we reached master's level all that was thrown out of the window and the truth was that, those techniques are only there to serve nothing but regulatory and statutory requirements. Corporate ethics is practically non-existential.

The way scandals are exposed are almost always through whistleblowers. That is a fact. If you want transparency and honesty in a system, establish a bounty system and protect the whistleblowers.