I have heard the following line in the TV series Marseille:
- Elle a réagi bien, comme si elle était déjà au courant. Ça a dû filtrer de l'évêché ou du palais de justice.
Context: The former mayor of Marseille and current Marseille soccer team president Robert Taro has found out that henchmen connected to the French Party were involved in the death of a young woman in a confusion after a soccer game. Supposedly, they caused the incident to convince the people that keeping the Marseille stadium public is a bad idea and that it should be sold. Taro leaks this info to the Press, but the current mayor Jeanne Coste, which is a member of the French Party, unexpectedly reacts calmly and counters the accusations with good arguments in a public statement. Due to this, Taro becomes suspicious that someone has leaked the info to her and shares his thoughts with his former politic rival Barrès saying the line above.
What does "évêché" mean here? Word Reference and Larousse dictionaries say it means "territory of a diocese" or a "bishop's palace", but the Catholic Church has nothing to do with this context and therefore the word means something else here.