Well one of the most famous examples would be Anne Frank; and yes, there are seemingly endless examples of people hiding Jewish persons and being discovered or denounced.

The family holding Anne Frank, for example, was denounced and raided by German police. The families hiding there were all deported, those of Jewish descent to various labor or death camps, and the rest sentenced to hard labor. Of course, punishments varied, summary execution and purging was not uncommon, as the Germans made very little effort to distinguish between Communists, Jewish persons and Partisans. The results appear to be mixed and certainly racially or politically motivated; if you were a Jew, deportation or eventual death was almost guaranteed. A partisan; similar. A collaborator or hider could be held by the Gestapo, executed, made a political prisoner or forced into hard labor.