Mithril Capital raised over $1 billion on the name of Thiel, one of Silicon Valley’s biggest celebrities. Now federal investigators are looking under the hood. Mithril’s leader, Ajay Royan, has worked with Thiel for almost two decades and has used that relationship to raise over $1 billion. But in recent years, Royan has frustrated some of his investors by sitting on some of their money rather than investing it in startups — while almost certainly raking in millions of dollars in fees for himself. The firm has lost staff and has adopted a more defensive posture. Two of the other managing directors at Mithril, Crystal McKellar and Jim O’Neill, recently left the venture capital firm in contentious exits, the people say — departures that until now haven’t previously been reported. Those two departures have essentially stripped a shop with more than $1.2 billion in assets down to a bare-bones operation whose remaining senior full-time employees consist of Royan, CFO Anuja Royan (his sister), and a close ally named Paul Leggett.