Conspiracy theories are prevalent among the public. Governments frequently release official documents attempting to explain events that inspire these beliefs. However, these documents are often heavily redacted, a practice that lay epistemic theory suggests might be interpreted as evidence for a conspiracy. To investigate this possibility, we tested the effect of redactions on beliefs in a well-known conspiracy theory. Results from two preregistered experiments indicate that conspiracy beliefs were higher when people were exposed to seemingly redacted documents compared to when they were exposed to unredacted documents that were otherwise identical. In addition, unredacted documents consistently lowered conspiracy beliefs relative to controls while redacted documents had reduced or null effects, suggesting that lay epistemic interpretations of the redactions undermined the effect of information in the documents. Our findings, which do not vary by conspiracy predispositions, suggest policymakers should be more transparent when releasing documents to refute misinformation.