Financial Misconduct - What to do?

Looking for some advice from the group. I recently became aware that between 2020 and 2025, one of the then new hires - hired as an endowed chair - was never actually on a faculty line. Instead, and this is incredible, they paid him using the principal of the endowment in order to meet his salary demands. Now, here were are in 2026. He lost his chair in 2025 (for other reasons) and the chair itself disappeared. In total, roughly 1 million was spent on this shady endeavor. I've raised this issue with my department chair and associate dean but, because both are tangentially complicit, they have said we just have to live with it. I'm not going to live with it, but I'm not sure where to go next because I am fairly certain the university will close ranks. Any thoughts where I should go next?

*As a note, the donor of the endowed chair passed was over 35 years ago (that was my first stop).

*I am tenured and I use my tenure solely to call out BS in the college, so I'm not worried about retribution.