The Swiss position: no general obligation
Swiss law takes a restrained approach to whistleblowing. Parliament has repeatedly declined to enact a dedicated whistleblower statute for the private sector, so there is no general rule requiring companies to set up a reporting channel, and no comprehensive statutory protection for employees who report wrongdoing. What exists instead is the general framework of employment law: the employee's duty of loyalty (Art. 321a CO) on one side, the employer's duty to protect the employee's personality (Art. 328 CO) and the rules on termination (Art. 335 CO) on the other, and case law that broadly expects concerns to be raised internally before they are taken outside.
That last point is the quiet argument for a channel: Swiss practice pushes reports inward first. A company with no credible internal route leaves an employee who discovers a problem with a choice between silence and escalation, neither of which serves the company.
Where the answer is different
Three categories of company should not rely on the "no general obligation" headline. Listed companies face governance expectations from investors, proxy advisers and codes of best practice that treat a functioning reporting mechanism as standard. FINMA-regulated firms must maintain an adequate compliance organisation, and supervisors expect serious internal irregularities to surface and be handled: a reporting channel is part of how that is demonstrated. And Swiss groups with subsidiaries in the EU are within reach of the EU Whistleblowing Directive: entities above the member-state thresholds must operate reporting channels under local law, and many groups sensibly extend one system across the whole group, Switzerland included, rather than run two regimes.