Not sure if belongs in Criminal or Tax Need Help Quick Please

I have situation and I'm not sure where to turn. I'm not sure if this belongs in the tax forum or the criminal forum so I'm cross posting. If a moderator will direct it to the appropriate location please do, I just googled and found this forum. Thank you for your understanding and help in advance.

The breakdown of the facts and suppositions as I know them,
A. Approximately $1,500,000 of businesses income is from credit cards and accounts.
B. Over half of the business is comprised of cash and various forms of traceable income, other than that listed in point A.
C. I know that although sales tax was collected on all sales listed in point B, the only sales tax that was paid to the state was based on point A.
D. I strongly suspect that the only income filed on corporate tax return was from point A.
E. I have a strong suspicion that these practices have been occurring for the past several years.
F. If anyone was tipped off, it would be obvious where the tip came from.
G. I also have no doubt that there would be retaliatory action taken.
H. Do to certain circumstances, I don't feel the local enforcement can be trusted with this.
I. I have a copy of the .QBB file, to use as corroboration.

Ok, that being said, I have been given the advice from a close friend to walk away from the whole situation. However, I have an overwhelming moral compunction to “do the right thing” and that would mean not walking away.
If I choose to see this through, given the above information who do I turn to, and also IF (and this one is a big one), If I decide to go through with this, would witsec or a similar program be a legitimate option? I want to see the right thing done, but I would just as soon keep breathing also.
By the way, I'm in Florida
Thank you for any help or guidance.

I doubt you'd get witness protection. Also, you may have a duty under the federal financial privacy laws not to reveal any info you learned, depending on your relationship to the company when you learned of this. Keep in mind the facts you presented do not prove that the state sales tax paid was wrong. The tax would only be imposed on in-state sales. If the company does a lot of mail order sales, their returns may be correct.

Well, actually that's the problem. I was an employee of the company, and partially responsible for the record keeping. All the sales were in state. So, that leads to another question. Is there anything I need to be concerned about as far as my culpability? I had nothing to do with the “cash” side but was aware of the practices.

At this point you need to talk to a white-collar crime atty so you'll be protected by priviledge. And malpractice insurance.

Understood, Thank you for your quick response.