Sageo-Tapungu, StephanieSissons, HelenTheunissen, Petra2026-04-012026-04-012026-03-18Media International Australia, ISSN: 1329-878X (Print); 2200-467X (Online), SAGE Publications. doi: 10.1177/1329878X2614253151329-878X2200-467Xhttp://hdl.handle.net/10292/20857The term 'kastom' broadly refers to the traditional systems of beliefs and values found across the islands of Melanesia, encompassing indigenous knowledge passed informally between generations through oral traditions. While these systems vary between communities, in Papua New Guinea (PNG), the region's largest and most linguistically diverse nation, 'kastom' continues to inform professional life, including the practice of journalism. This article explores the relationship between 'kastom' and news reporting in PNG through a combination of video ethnography and semi-structured interviews. Drawing on Melanesian research methodology, the study shows how journalists themselves understand their profession and examines whether existing Western-style journalism training adequately prepares journalists for practice in PNG. The discussion highlights the difficulties and negotiations journalists encounter as they balance professional expectations with social and cultural obligations. The paper outlines core principles of kastom, as expressed through the wantok system, a network of kinship and reciprocal obligation, and illustrates how these norms inform the everyday experiences of journalists. While the study is interpretative rather than normative, the authors propose the concept of ‘polite watchdog’ as a culturally grounded framework that describes how journalists critically engage with powerful sources while maintaining respect for 'kastom'. This model suggests that democratic accountability can be pursued in ways consistent with local epistemologies, offering insights for other postcolonial contexts where Western journalism frameworks intersect with indigenous practices, such as in Fiji, Vanuatu or parts of the Caribbean.© The Author(s) 2026. Creative Commons License (CC BY 4.0). This article is distributed under the terms of the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).16 Studies in Human Society19 Studies in Creative Arts and Writing20 Language, Communication and Culture3605 Screen and digital media4701 Communication and media studiesPapua New Guineakastomwantokmultimodal analysisconversation analysiscritical discourse studiesvideo ethnographyjournalismpolite watchdogJournal ArticleOpenAccess10.1177/1329878X261425315