This mid-seventies american series produced by Darren McGavin who also starred as the series hero Carl Kolchak, started as two made for TV movies, The Night Stalker and The Night Strangler. It is very much a precursor to the X files. Kolchak is a reporter who has a knack for investigating the unconventional stories, normally involving some aspect of the supernatural  and while he always gets his monster, his stories are never published, but just filed instead.