In the first Australian study of its kind, paternity testing was shown to have the overwhelming support of the general public.* However, the use of paternity testing without the knowledge of the mother, or “motherless testing” was found to be more controversial. Through the analysis of a series of focus groups conducted as a follow up to the national monitor of public opinion on attitudes to new technologies, including DNA paternity testing, this paper examines these controversial attitudes to paternity testing in more depth. The results suggest that public attitudes are informed by media generated knowledge based on high profile cases of disputed paternity, such as in ‘misattributed paternity’ and ‘paternity fraud’. Through an analysis of the focus group data, the paper traces the construction of a discourse around “paternity fraud” and assesses its currency in public opinion. Finally, the discursive practices enabled by this shift in public understanding are examined in light of the corresponding decline in support for paternal obligation.