Lets face it CO from the exhaust would probably include all the other horrible stuff that stinks.
Even a miss placed crank case vent put fumes in the cockpit that made me feel ill.
That's my experience.
So why haven't the AAIB lifted the aircraft.
Surely they needed to examine the engine.
If i was a operator of that type, i would want some answers.
Why, is something being hidden.
I'm quite sure even amateur wreck divers could bring it up.