E/CN.4/2004/56/Add.2 page 19 groups and individuals claim that torture and ill-treatment by State security and police forces is systematically used. The Special Rapporteur believes that he should not only acknowledge that such divergent views exist, but that he also has the duty to draw further conclusions on the basis of his own findings. In this regard, he attaches great value to the opinion of credible interlocutors from the judiciary, the academic world and civil society that certain actors and militants supporting radical Basque causes may well use as a tactic the systematic practice of trumped-up allegations of torture and ill-treatment. At the same time, these interlocutors also conveyed their opinion to the Special Rapporteur that security and law enforcement agents, particularly in their counter-terrorist activities, do resort more than sporadically to practices that constitute torture or cruel, inhuman or degrading treatment. This opinion was shared by a considerable number of non-governmental organizations that the Special Rapporteur met and was confirmed by a series of testimonies presented to the Special Rapporteur by persons who had been arrested, detained and interrogated by the State security and police forces. These statements referred to treatment that included beatings, exhausting forced physical exercises, asphyxiation by placing plastic bags around the head (“bolsa”) and humiliating sexual harassment. It is the considered view of the Special Rapporteur, in the light of the internal consistency of the information received and the precision of factual details, that these allegations of torture and ill-treatment cannot be considered to be fabrications. The Special Rapporteur does not conclude that the treatment just described would constitute a regular practice but, in his view, their occurrence is more than sporadic and incidental. 59. The Convention sets out a series of obligations to prevent and suppress practices of torture and ill-treatment. Great importance must be attached to the obligation to undertake a prompt and impartial investigation whenever there is reasonable ground to believe that an act of torture has been committed (art. 12) and to the duty to have allegations and complaints of torture promptly and impartially examined (art. 13). The Spanish legal system does provide for investigative mechanisms and procedures, but there are a number of reasons why this investigative capacity is underutilized and often ineffective. The denial that the practice of torture or ill-treatment occurs, the deterrent, repeatedly reported to the Special Rapporteur, that allegations of torture are countered by criminal charges of defamation, and the questionable independence and impartiality of internal accountability mechanisms with regard to law enforcement officials21 are among the factors that contribute to the absence of an effective and prompt investigative practice and policy as regards the issue of torture and ill-treatment. 60. The Special Rapporteur fully shares the view repeatedly expressed by CPT that experience has shown that it is in the period immediately following deprivation of liberty that the risk of intimidation and physical ill-treatment is the greatest.22 It is crucial that in this period of police custody effective safeguards against torture and ill-treatment be ensured. These safeguards must weigh the more heavily when persons are held in incommunicado detention, as provided for in the Spanish Code of Criminal Procedure with respect to persons suspected of certain categories of crimes, including membership in or connection with an armed group, terrorists or rebels. The issue of incommunicado detention is always of special concern to the Special Rapporteur in view of the opinion repeatedly expressed by the Commission on Human Rights that prolonged incommunicado detention may facilitate the practice of torture and can in itself constitute a form of cruel, inhuman or degrading treatment, or even torture.23 It is during this period that the