Please note that policy and posters alone would not help. As an employer, you need to train the employees on what the policy means, its application, etc.
Its important that employees are aware of the reason why the Act 2013 has been put in place and the penalties involved in reporting a false case. As an employer, you have to treat this inline with your CoC-Raising False Alarm, Complaints, etc.
Raising a false complaint damages the reputation of the alleged respondent. Therefore, it needs to be seen in that light and treated very seriously.