We investigate the effects of psychological safety and auditor knowledge on subordinates' willingness to share privately known, fraud-relevant information during brainstorming. We test a model illustrating how partner leadership affects subordinates' perceptions of psychological safety (P-S), which then affect brainstorming differentially depending on the level of subordinates' task knowledge. Participants watch a video of a simulated brainstorming session in which we manipulate P-S by altering how the partner communicates. In the more (less) P-S condition, the partner engenders a supportive (non-supportive), non-threatening (threatening) group dynamic and a style that encourages (discourages) idea sharing. We predict and find that less-knowledgeable auditors increase their willingness to share privately known, fraud-relevant information in a more P-S setting than in a less P-S setting; there is no effect of differential levels of P-S on more-knowledgeable auditors' changes in willingness to share such information. This implies the criticality of encouraging team dynamics that engender P-S for less-knowledgeable subordinates.