The digital transformation of government initially focused on the internal processes and work practices of government agencies, and then on the channels and ways of services provision to citizens and firms, as well as on the services themselves, and aimed mainly to increase efficiency. However, later it was extended towards the enhancement of government transparency and accountability, by exploiting the digital technologies in order to provide large amounts of information to citizens and firms about the activities and plans of government agencies, and recently to open and publish large datasets of them. This constitutes a big innovation/transformation, since previously government data were regarded as highly secret, and could be accessed only by limited numbers of competent public servants. The Open Government Data (OGD) have a great potential to promote not only government transparency and accountability, but also economic development (especially concerning the emerging data economy), scientific research as well as efficiency and effectiveness of other government agencies (beyond the one who publishes them). However, the OGD domain is relatively new, rapidly evolving, and has not reached and realized its full potential, so extensive research is required in order to support and facilitate progress in this direction, and finally increase the social and economic value generated from the large amounts of published OGD. So, it is quite important to define rationally the research agenda in this OGD domain: the main research areas as well as the particular research topics of each of them. For this purpose, some research has been conducted, which however is based exclusively on the review and analysis of previous scientific papers in this domain. In this paper we investigate the exploitation of recent OGD-related policy as well as legislation documents, as an additional and complementary source for extracting areas and topics in the OGD domain that require research in the near future. A methodology for this is developed, which is used in order to we analyse the ‘OECD Open Government Data Report – Enhancing Policy Maturity for Sustainable Impact’ and the EU Directive 2019/1024 on ‘Open Data and the Re-use of Public Sector Information’. This results in the identification of interesting new areas and topics of required OGD research, which are highly important and have not been identified by previous relevant research based on the review and analysis of scientific papers in this domain.