Article 51 of Regulation 2016/679 must be interpreted as meaning that a court having jurisdiction to authorise disclosure of personal data to another judicial body does not constitute a supervisory authority within the meaning of that article, where that court is not entrusted by the Member State in which it is situated with monitoring the application of that regulation in order to protect, in particular, the fundamental rights and freedoms of natural persons in relation to the processing of their personal data.