The West Midlands Police and Crime Commissioner is to be taken to an Employment Tribunal by his one-time deputy.
Yvonne Mosquito had been suspended back in March after she paid a visit to relatives of a teenage murder victim; Kenichi Phillips, aged 18, had been shot dead in the Ladywood area of Birmingham.
It was alleged that Mr Phillips’ family were upset by her arrival and her requests for them to pray with her.
A couple of months later she was found guilty of serious misconduct, with an independent panel finding she had caused the bereaved relatives “upset and distress.”
David Jamieson, Ms Mosquito’s boss, said that the incident had made it more difficult for the force’s officers to investigate the killing.
Ms Mosquito, who had also served alongside Mr Jamieson’s predecessor Bob Jones, had left her post in May.
Now it has emerged that she is taking the case to an Employment Tribunal. A hearing has been listed for next year according to HM Courts and Tribunal Service.
Both Mr Jamieson and Ms Mosquito have declined to comment on proceedings.