is decisive is whether the fear can be objectively justified’667 and that the fear is one that is reasonable. 91. The principle of impartiality demands that:    Both judges and juries be unbiased; Proceedings are conducted fairly; and Decisions made solely on the evidence.668 92. The fact that a judge has dealt with the accused on a previous occasion will not necessarily cause the proceedings to be unfair. The key issue will be the nature and character of the previous decision.669 Where the prior involvement with the individual concerned the same or a related matter, this increases the likelihood that the proceedings will be unfair.670 93. Similarly, if the identity of judges are concealed, this also undermines their independence.671 94. The independent and impartial role of prosecutors is also crucial in the context of ensuring a fair trial. The UN Guidelines on the Role of Prosecutors sets out guidelines to ensure their impartiality and independence.672 Anonymous judges, religious courts, Courts Martial, Military Tribunals, military judges Anonymous/’faceless judges’ 95. Although the Human Rights Committee has treated trials with anonymous judges as contrary to the requirements of independence and impartiality, this may not be the case on every occasion if this is done in the context of compliance with the requirements for derogation under Article 4 of the ICCPR.673Such trials will, however, be treated with considerable caution.674 Religious courts 96. The Human Rights Committee has applied certain conditions to religious courts or those based on customary law. These are that: a. The proceedings should be limited to minor civil and criminal matters; b. They must meet the requirements of fair trial and other relevant guarantees of the Covenant; 667 Communication 1122/2002, Castedo v Spain, UN 20 October 2008, para 9.8. See the Human Rights Committee decisions: Communication 387/1989, Kartunnen v Finland, 23 October 1992, and Communication 356/1989, Collins v Jamaica , 25 March 1993, and European Court, Fey v. Austria, 24 February 1993 669 European Court, Hauschildt v Denmark, 24 May 1989. 670 European Court, Fatullayev v Azerbaijan, 4 October 2010; Chesne v France, 22 April 2010. 671 Inter-American Court, Castillo Petruzzi v Peru, 4 September 1998, Series C No.41 (1998). 672 As adopted by the UN Congress on the Prevention of Crime and the Treatment of Offenders, Havana, Cuba, 27 August – 7 September 1990. 673 Communication 577/1994, De Polay v Peru, UN 6 November 1997. 674 Communication 1058/2002, Mas v Peru, , 16 November 2005. 668 116