Prescription opioid diversion and use for non-medical purposes is a growing problem linked to crime and addiction. While offenders are more likely than the general Australian population to use prescription drugs for non-medical purposes, relatively little is known about the types of prescription opioids they use and their patterns of use. Identifying the extent and nature of prescription opioid use among police detainees may assist law enforcement agencies and healthcare providers to allocate resources more effectively. This bulletin draws on data from the Drug Use Monitoring in Australia (DUMA) program collected in January and February 2016. One-quarter of detainees reported prescription opioid use in the last 12 months and almost a fifth engaged in non-medical use of these drugs. The most commonly reported opioid was buprenorphine, and opioids were most commonly obtained from a family member or friend or purchased from a street dealer. About four in 10 users had used more than one type of prescription opioid in the past 12 months, and most had also used other illicit drugs.