The entanglement of border control technologies and immigration policies and practices with discourses of race, national identity and belonging has long been a focus of scholarly interest. In this paper we discuss the Human Provenance Pilot Project (HPPP), the aim of which was to evaluate the utility of genetic and isotope testing to corroborate asylum seekers’ accounts of their nationality. We subject the HPPP to a detailed socio-technical analysis, highlighting how technologies, practices and modes of thought travelled from the policing context to the asylum context, illuminating the unspoken prejudices that made that transfer possible, and reflecting on implications of the HPPP for academic research, policy advice and the asylum system.