Something else in the public interest
Public-interest concerns arising through work (whistleblowing).
Whistleblowing law identifies 'prescribed persons' and regulators for particular sectors. The right body depends on the subject — financial services, health and care, environmental regulation, workplace safety, data protection and so on.
For non-immediate workplace disclosures, identify the correct prescribed regulator before sending confidential material. Where there is an immediate danger or crime in progress, use the emergency/police route first. Avoid publishing personal, commercially sensitive or security-sensitive material publicly merely to create a record — use the appropriate protected reporting route.
Record what happened, when, where, who was involved, what evidence exists, and what harm or risk you believe results.