Employees and Former Employees  Employee and former employees are the most common whistleblowers. The law protects employees who file an action, or who assist in furthering an action, against job retaliation by the employer. See, Don’t Whistleblowers risk getting fired?
Competitors and Subcontractors  A competitor (or its employee) who has direct knowledge of the fraud may file suit.
Federal Employees  The Federal Act does not specifically exclude federal employees. 
Public interest groups, corporations and other private organizations  Organizations as whistleblowers have raised questions as to whether they can meet the “public disclosure” provision of the law. Some courts have dismissed organizations as whistleblowers for not being able to meet that provision. If your organization has a question contact a lawyer.

“Close observers” and even participants in a fraud may blow the whistle and receive compensation for their efforts. The federal law permits a court to reduce the reward to a wrongdoing whistleblower “to the extent the court considers appropriate.”

However, if you have participated in any fraud against any government you must stop and you should seek legal counsel to help you evaluate whether you may have any criminal liability or not.