I'd recommend you get out of there in that situation. I've personally had something similar and it wasn't fun being caught in the wreckage when it turned out the CEO had lied about certain investments.
Unless you want to do more business specifically with said investors, I would not recommend this. Whistle blowers almost always suffer and in this situation you have no moral obligation to the public but rather to some private figures. If I were you, I'd enjoy having an easy job. That said, is your company hiring?