I have a female member of staff who is being picked on by another member of staff (male) who she beat in a fair promotion interview. This manifests itself in two forms

1) verbal, calling her derogatory names to her face and, behind her back telling people clear untruths.
2) pinning items up on notice boards (he has been seen but the people are unwilling to come forward for fear of reprisals)

Does the company have a duty to prevent this, and without the evidence how should it be tackled.

Regards

Paul Wynne