The basic question in this consultative opinion was: In case of Genetically Modified Organism (GMO) contamination in non-GMOs crops, especially in absence of national legislation, who is responsible to pay the damage among all the different public and private actors involved in the GMO chain of production, distribution and dissemination? The applicant stated that he was concerned about the spreading of genetically modified organisms into traditional crops, especially without prior informed consent by the farming community. The applicant clarified that his interest concerned in particular: a) Brazil and Pakistan, where cases of smuggling of GM seeds had occurred despite a national moratorium on GMOs; b) The regime of liability in case of GM contamination in a certain country proceeding from Food Aid agencies. The court analyzed the problem of coexistence between conventional farming and GM farming, outlined basic issues of liability for GMO’s international and supranational liability regimes, examined the inadequacy of traditional liability in tort or under the law of neighbor relations as well as the new generation of GMO liability laws relating to coexistence and finally analyzed the responsibility of food aid agencies for GM contamination. It concluded that the analysis of the various liability regimes clearly showed the inadequacy of traditional tort and neighbourhood liability in tackling the complex liability issues raised by genetic contamination. The new generation of liability laws in the field of biotechnology, including genetic contamination, normally provided for strict liability and thereby removed the obstacles of fault and negligence or balancing requirements. Liability normally was civil in nature. However, there were also examples of administrative liability, especially with respect to the beneficiary of compensation and the determination of damage. Then, pure ecological damage or socio-economic damage could be covered. Under public international law, states and international organisations were in principle responsible for their food aid agencies when the latter had breached a rule of public international law and caused damage to the recipient state. However, it was highly doubtful whether the mere omission to inform the recipient state about the GM properties of food supplied would lead to responsibility. International law was quite reluctant to recognise preventive information obligations and the necessary threshold of harm may not be surpassed. The violation of the advance information obligation for GM food set forth in article 11 Biosafety Protocol by a contracting party may course give rise to responsibility under public international law if the threshold of damage was surpassed. Besides, the violation of national rules regarding the import of GM food adopted by a contracting party in implementing the protocol in national law may render the importer liable for damages under national tort law.