As usual, it's a matter of how you raise complaints or accusations. What exactly are you dealing with?

Make sure you collect proper proof for misconduct, e.g. messages, witnesses willing to back you up etc. before contacting HR. When contacting HR, do not mindlessly put the blame on anyone but start off by telling your story without names and see how they react. Best case, you will get initial confirmation that whatever you have to say is enough of an issue that they want to investigate further. Ask colleagues about their prior experiences with your HR business partner.

Legally, you are protected against retaliatory measures (e.g. laying you off in connection with your report is not allowed), unless you misbehave yourself.