Before you report anything, you need to assess whether what you have observed is actually unlawful. Sometimes, someone may have done something that appears to be illegal or unethical but, upon investigation, it is not in fact a legal violation. You should engage with someone who is an expert in assessing such issues to help you understand whether this is a real issue and, if so, what to do about it. Basically, you should talk to a lawyer.
You can contact one of us, of course. Another option would be to contact an organization such as Ethic Alliance (here's a link to the Ethic Alliance website). In either event, you should speak to a lawyer immediately so that they can analyze the issues, tell you about how to obtain and preserve information, and assist you in getting the proper authorities involved, as appropriate.
In our experience, people in your situation are just trying to do the right thing. And often they are interested in making their employer or organization do the right thing, too. Unfortunately, such employees are often viewed as troublemakers or as disloyal to the organization. When that happens, the employer (or even fellow employees) can turn on the employee and seek to discredit them or negatively affect their employment status. A lawyer can help address this reaction.