<p>While interest towards AI ethics grows, it remains challenging for companies to implement in practice. Some existing studies have sought to understand the current state of practice in AI ethics and the challenges companies face while trying to take ethics into account. However, there is still work to be done in this regard. Specifically, we consider the viewpoint of roles in the practical implementation to be underexplored. In other words, "who" should be doing AI ethics? We conduct an exploratory multiple case study to understand how three companies tackle AI ethics, especially in terms of roles. We conduct semi-structured interviews with respondents working in both management and developer roles. The resulting interview data is analyzed using thematic analysis. Our results showcase different ways in which AI ethics can be approached as far as roles are considered. Our case companies employ different approaches to AI ethics and, in addition, also discuss likely future scenarios for their organizations, as well as how they perceive things should be ideally done. In addition, we present a framework that highlights four general ways to approach AI ethics in terms of roles and responsibilities. This study furthers our understanding of how AI ethics is approached in practice in terms of organizational roles and processes, serving as an initial exploration on the topic. The framework we propose provides a tangible way to start considering roles related to AI ethics in both research and practice.</p>