failed to identify victims early. It recommended that the UK authorities broaden the scope to cover all such offences and ensure that law enforcement agencies receive training to support early identification.22 11. For these reasons, the intervenors submit that deprivation of citizenship is analogous to prosecution and amounts to punishment, causing victims of trafficking further harm and interfering with their recovery as well as reintegration (see Section III).23 It is particularly harmful where deprivation leads to statelessness, or if it is conducted without prior criminal proceedings or due procedural safeguards. b. Procedural obligation to conduct an effective investigation 12. The obligation to investigate arises where there is a credible suspicion that rights under Article 4 have been violated, 24 and drawn to the attention of the authorities including, inter alia, through contact with law enforcement agencies and legal assistance requests.25 Where a potential victim of trafficking is known to the authorities, this presents a clear opportunity for the authorities to investigate the individual circumstances further. The obligation is one of means not result26 and covers all stages from recruitment to exploitation (while reiterating that the ‘means’ element does not apply to child victims).27 When recruitment occurs on a Contracting States’ territory, that State should conduct the investigation into the recruitment.28 13. The Grand Chamber of this Court has made clear that authorities “must take whatever reasonable steps they can to collect evidence and elucidate the circumstances of the case”.29 The conclusions of the investigation must be based on a thorough, objective, and impartial analysis of the relevant material obtained. The investigation must be independent; capable of identifying and punishing those responsible; prompt; and involve the victims to the extent necessary to ensure their safeguarding.30 14. National authorities are required to act of their own motion and must not leave the initiative to the responsibility of the victim to have made a complaint. 31 They should consider the wider context relevant to the identification of potential victims of exploitation. In Chowdury, the Court considered that Greece had violated the procedural limb of Article 4 as the prosecutor had refused to bring proceedings in respect of twenty-one applicants on the grounds that, among other things, they had lodged their complaints belatedly.32 The Court concluded that there was “nothing in 22 GRETA, Report Concerning the Implementation of the Council of Europe Convention on Action against Trafficking in Human Beings by the United Kingdom (3rd evaluation round) GRETA(2021)12 (Council of Europe, 20 October 2021), §§160 and 171, page 83. See also Modern Slavery Act 2015, Sch.4 23 Siobhán Mullally, UN Special Rapporteur on Trafficking in Persons, states that “[D]eprivation of citizenship, without accompanying protections or procedural safeguards, is in itself a form of punishment” in Reprieve, Trafficked to ISIS, (2021). 24 C.N. v. the United Kingdom, op. cit., § 69; Zoletic and Others v. Azerbaijan, no. 20116/12, § 193, 7 October 2021; B.B. v. Slovakia, no. 48587/21, § 87, 24 October 2024. 25 Zoletic and Others v. Azerbaijan, op. cit., §§ 199, 200; V.C.L. and A.N. v. the United Kingdom, op. cit., §117. 26 J. and Others v. Austria, op. cit.; Chowdury and Others v. Greece, op. cit., § 116. 27 V.C.L. and A.N. v. the United Kingdom, op. cit., §149. 28 Rantsev v. Cyprus and Russia, op. cit., § 308. 29 S.M. v. Croatia [GC], op. cit., § 316. 30 Chowdury and Others v. Greece, op. cit., § 116 and 117; Rantsev v. Cyprus and Russia, op. cit., § 288. See also S.M. v. Croatia [GC] op. cit., § 313. 31 V.C.L. and A.N. v. the United Kingdom, op. cit., § 155. 32 Chowdury and Others v. Greece, op. cit., § 117-121. 3