A/HRC/23/46 the person’s physical state or mental capacity, or technical reasons such as lack of transport capacity, or failure of the removal due to lack of identification. When removal has been postponed, Member States should ensure family unity, emergency health care and essential treatment of illness and access to basic education for children, and that the special needs of vulnerable persons are taken into account. 92. Art. 15 provides that detention for the purpose of removal shall only be used if other sufficient but less coercive measures cannot be applied effectively in a specific case, particularly when there is a risk of absconding, or the person concerned avoids or hampers the preparation of return or the removal process. 93. Detention shall only be ordered by administrative or judicial authorities, in writing with reasons being given in fact and in law, and must be subject to speedy judicial review upon request. The third-country national concerned shall be released immediately if the detention is not lawful. The Directive further prescribes a maximum period of detention of 6 months, which may be extended exceptionally to maximum 18 months. When no reasonable prospect of removal exists, a person shall be released immediately. 94. Art. 16 imposes minimum conditions of detention. Detention shall take place as a rule in specialized detention facilities. Third-country nationals in detention shall be allowed - on request - to establish in due time contact with legal representatives, family members and competent consular authorities, and particular attention shall be paid to the situation of vulnerable persons. Emergency health care and essential treatment of illness shall be provided. Relevant and competent national, international and nongovernmental organisations and bodies shall have the possibility to visit detention facilities. 95. Art. 17 limits the detention of children and families, who should only be detained as a measure of last resort and for the shortest appropriate period of time. The best interests of the child shall be a primary consideration in the context of the detention of children p ending removal. 96. A Commission Communication evaluating the implementation of the Return Directive is scheduled for December 2013. 2. The European Return Fund 97. In its Decision 575/2007/EC, the European Parliament and the Council established the European Return Fund as part of the General Programme “Solidarity and Management of Migration Flows”. The general objective of the fund is to support the efforts made by Member States to improve the management of return through the use of the concept of integrated management and by providing for joint actions to be implemented by Member States or national actions that pursue Community objectives under the principle of solidarity, taking account of Community legislation in this field and in full compliance with fundamental rights. The actions eligible for support include the facilitation of voluntary returns and the simplification and implementation of enforced returns. 98. The European Return Fund provides for significant funding (630 million euros over the period 2007-13) to support the efforts made by EU States for returns. It will be absorbed by the future Asylum and Migration Fund. 3. Readmission Agreements 99. Article 79.3 of the Treaty on the Functioning of the European Union provides that the EU may conclude agreements with third countries for the readmission to their countries of origin or provenance of third-country nationals who do not or who no longer fulfil the conditions for entry, presence or residence in the territory of one of the Member States. 39