The right to liberty and security In addition, international human rights law strongly discourages deprivation of liberty of children alleged, accused or recognised as having infringed penal law. That raises the question of whether or not detention of children who are not in conflict with criminal law can be justified at all on immigration-related grounds. Immigration detention of children is contrary to international human rights law, in the opinion of the UN Working Group on Arbitrary Detention, the UN Committee on the Rights of the Child and the Special Rapporteur on Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment. FRA opinion 2 To protect the right to liberty and security (Article  6 of the Charter), EU  Member States are encouraged to introduce more favourable provisions in national laws – as envisaged in Article 4 (3) of the Return Directive and Article 4 of the Reception Conditions Directive – either prohibiting or further restricting the possibility to detain children for immigration purposes. This would significantly contribute to avoiding the risk of arbitrary detention of children. Concerning asylum detention, the current reform of the asylum acquis is an opportunity for EU  legislators to take a  stronger stand against child detention. EU  Member States should systematically collect disaggregate data on children in immigration detention, while the European Commission should encourage the comparability of such data through Eurostat. 31