According to the ECtHR's Press release:

The case concerned the repeated refusal of Polish border guards on the border with Belarus to admit the applicants, who had come from Chechnya and had asked for international protection.

The Court found in particular that the applicants had repeatedly arrived at the Terespol border crossing between Poland and Belarus and had made it clear, despite the Polish authorities’ statements to the contrary, that they wished to seek international protection.

Instead, the border guards had returned them consistently to Belarus, without a proper review of their applications. Furthermore, the Government had ignored interim measures issued by the European Court to prevent the removal of the applicants, who had argued that they were at a real risk of chain-refoulement and treatment contrary to the Convention.

The Polish State had demonstrated a consistent practice of returning people to Belarus in such circumstances, a policy which amounted to collective expulsion. Given the authorities’ refusal to implement the Court’s interim measures, the Polish State had also failed to live up to its obligations under the Convention.

The ECtHR held, unanimously, that there had been: a violation of Article 3 (prohibition of torture or inhuman or degrading treatment) of the European Convention on Human Rights, a violation of Article 4 of Protocol No. 4 (prohibition of collective expulsion of aliens) to the Convention, and a violation of Article 13 (right to an effective remedy) of the Convention, in conjunction with Article 3 and Article 4 of Protocol No. 4. It also held, unanimously, that Poland had failed to comply with its obligations under Article 34 (right to individual petition) of the Convention.