Gather proof. Document everything properly. Raise POSH, the panel has to have external people in the committee as well. Genuinely consider legal action and let the office folks know that is something you would graduate to. Expose the guy on linkedin and X, no one should go through this again. Your wife may have to change organisations because this would have unsaid repercussions. More importantly, you may confront this person directly. Being the husband, her safety is your responsibility. Rather try both approaches parallely. Break this MF.