Establishing criminal liability for environmental offences remains daunting, particularly with regard to the ‘no plaintiff—no judge’ element as a result of which the public seems to be ultimately deprived of the possibility to participate in criminal environmental proceedings. While there is arguably a lack of specific instruments at the European Union (EU) level which would prescribe such legal obligation on the part of the State, there has been a shift in understanding the role of the public and its participation in criminal liability cases, namely under the auspices of the so-called effective investigation and the concept of rights of victims in general. Using the example of the Czech Republic as a point of reference, this article aims to assess the relevant legal developments at both EU and Czech levels to illustrate why the non-governmental organizations (NGOs), essentially acting as public agents, should be granted an active role in environmental criminal proceedings. After examining the applicable legal framework and case law development, the article concludes that effective investigation indeed stands as a valid legal basis for human rights protection which incorporates an entitlement to public participation. Despite that, this pro-active shift is far from being applied in practice, implying that the legislation remains silent where it should be the loudest, and causing unsustainable behaviour of companies.