Would it be considered unethical to anonymously report my suspicion that several
As far as I can tell from your description, it would not be unethical to report such fraud--indeed, reporting it is likely the right thing to do. Depending on the details, it might even be illegal not to report it. You might want to consult a legal expert to determine your rights and responsibilities in this case. It sounds like you are in a bad company and a bad situation. I wish you the best as you try to make things better.