As per the discussion, we may not get the appropriate context, so for the benefit of anyone reviewing this entry subsequently, I am going to bet on "civil procedure" on the basis that several procedural codes are called this. Note my comment in the discussion that the appropriate term may be "civil proceeding" or something different based on the context.
https://libros.mercadolibre.com.ve/libros-fisicos/codigo-de-...
https://opac.um.edu.uy/index.php?lvl=publisher_see&id=1777
https://www.corteidh.or.cr/sitios/tesauro/tr1595.htm

I am not sure what context would result in "civil prosecution" being the appropriate term. A prosecution is either a criminal proceeding brought by the state or a patent enforcement proceeding brought by the patent holder. A "civil prosecution" is a rare thing indeed. It's a remedy that allows a private party to "prosecute" crimes as if they were standing in the shoes of the state.
https://www.ojp.gov/ncjrs/virtual-library/abstracts/civil-pr...

Without reams of additional context, I doubt we can infer that this is what was meant, and therefore I propose "civil procedure".