Competition authorities have developed various tools to detect cartels and substantiate the basis for opening investigations. Ex officio investigations, meaning investigations initiated by the authorities themselves, are derived from detection tools that require a higher level of proactivity from the agency, for instance, industry monitoring and cartel screenings. New technologies such as artificial intelligence also provide competition authorities with greater opportunities to improve their detection tools. This paper provides an overview of detection tools to launch ex officio cartel investigations, including recent trends and experiences from Latin America and the Caribbean. It concludes by highlighting the need for competition authorities to implement a variety of approaches to complement one another and enhance cartel detection.